Learn about vellum and how to paint on it
​

The history and nature of vellum

How to paint on vellum
  • ​​​Vellum and Art - traditional and contemporary painting on vellum - including an overview of the techniques
  • What is vellum -  what it is, how it is sourced; how it is made 
  • Different types of vellum - and an explanation of their  names ​
  • How to paint on vellum including a summary of tips from experienced botanical artists
  • How to mount vellum - and relevant suppliers
  • The conservation of botanical illustrations on vellum
  • Suppliers of vellum, pumice in the UK and USA and conservation materials 
Vellum - Originally, a translucent or opaque material produced from calfskin that had been soaked, limed and unhaired, and then dried at normal temperature under tension
The processes described on this page for the production of both vellum and parchment are essentially the same. 
  • vellum is derived from the skin of calves - and historically has been used for paintings by a number of the past masters of botanical art (particularly Ehret and Redouté) and the more important illuminated manuscripts. 
  • parchment comes from the skin of sheep - is typically whiter and has been used for centuries for important legal documents, calligraphy and illuminated manuscripts.
NOTE: All contemporary vellum and parchment production highlighted on this page is ethically responsible. ​It only uses the skins of animals who have died naturally or are generated as a by-product of meat production.
Banner image: Four tulips (Boter man, Joncker, Grote geplumaceerde, Voorwint) painted in watercolour on vellum by Jacob Marrel - a public domain image from the Metropolitan Museum of Art. Merian was the step-father of Maria Sibylla Merian and taught her how to paint on vellum.
Picture
Rolls of vellum and parchment at William Cowleys - the last vellum and parchment maker in the UK

Botanical Art on Vellum
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Vellum is far more durable than paper over time. 
​In the past - and the present - it has been used for legal and religious documents as well as for painting. The rationale is that the document needed to last for as long as the asset. Laws in the UK were also always written on parchment. 

In terms of art:
  • Vellum was used for all non-wall paintings prior to the production of canvas. 
  • Vellum was also used for illuminations in medieval manuscripts and books and was a common base for miniatures.
  • Botanical painters in the seventeenth and eighteenth centuries - such as Marrel, Ehret, Merian, Robert, Aubriet and Redouté- typically used vellum for their botanical illustrations.
A lot of the artwork by Ehret and Merian that can be seen online is in the form of engravings of their paintings.

​However their original watercolour paintings were painted on vellum.  See also an image by Maria Sibylla Merian below - dated 1693.
Picture
Pancratium by Georg Dionysius Ehret Watercolor and gouache, with traces of black chalk on vellum (Sheet: 18 9/16 x 14 13/16 in. (47.2 x 37.6 cm). Collection: the Metropolitan Museum, New York

Contemporary botanical painting on vellum
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Painting on vellum has become increasingly popular in the late 20th and early 21st centuries.
About 20% of the paintings in the first exhibition in the Shirley Sherwood Gallery in 2008 were on vellum supports (the rest were on paper or card and a very few on canvas). The discovery of such a high proportion of artists using vellum was intriguing. Why would they choose this difficult and expensive material instead of paper? 
​​The conservation of botanical illustrations on vellum: past, present and future
Rory McEwen revived the interest in vellum as a support for contemporary botanical painting. 

He routinely painted on vellum and it seems likely this is because he started his studies of botanical painting with the past masters who also painted on vellum. 

For example, he studied the techniques used by Redouté when he had the chance to view the two portfolios of 52 original watercolour paintings on vellum acquired by his brother in law Lord  Hesketh. This turned into a long-standing commission to paint roses for Lord Hesketh.
On his death, his Estate gifted the unused supplies of vellum owned by McEwen to The Hunt Institute of Botanical Documentation. In turn, these sheets of vellum are now gifted by the Hunt to talented botanical artists who are interested in working on vellum. Artists who have received McEwen Vellum include: Bobbi Angell, Susannah Blaxill. Jenny Braiser, Richard Carroll, Patricia Dale, Rosalia Demonte, Elisabeth Dowle, Jean Emmons, Linda Funk, Yvonne Hammon, Mieko Ishikawa, Katherine Manisco, Kate nessler, Jenny Phillips, Pamela Stagg, Jessica Tcheripine and Carol Woodin.

I've seen some simply stunning contemporary botanical paintings painted on Rory McEwen vellum!
Picture
Crop of Fritillaria Caucasicaa (1981) - one of the last paintings by Rory McEwen
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Catalogue of the 2016 exhibition by Brigid Edwards of her new paintings on vellum
Encouraged by (McEwen's) example, a new generation discovered the qualities of vellum: smoothness, luminosity, glow, depth, ivory or cream colour, are all remarked on; ‘like painting on butter’ said one of the artists interviewed, ‘the brush just flies’, said another. The translucency of watercolour pigment against vellum, creating the luminous quality of flowers, is therefore a major factor in the choice of support.
The conservation of botanical illustrations on vellum: past, present and future
Vellum is the perfect material for exploring the surface topography of plants. I often stretch it on board, and its response to watercolor and light can’t be found in any other material. Each piece is unique, and its warmth and modulation of color combine perfectly with the rendering of plant life.
Carol Woodin
Other contemporary botanical painters on vellum include:
UK Ireland USA Australia
REFERENCES

What is vellum?
​

​This guide focuses on vellum made from skin. ​The word vellum is derived from the Latin vitulus (calf), and its diminutive vitellus.

The product is durable and high-quality. Indeed it is archival as many books which are now centuries old and Acts of Parliament still survive because they were written on Vellum.  For example, approximately 85.5 – 90.5% of The Dead Sea scrolls were written on parchment made of processed animal hide known as vellum 
“All of humankind’s history is on parchment and vellum. Magna Carta was written on parchment. The Dead Sea Scrolls: parchment, in 435BC.”
Paul Wright
Picture
Vellum is derived from the stretched skins of calves. These are skins stretched and drying on frames (Visit to Cowley's 16.03.18)
Vellum can be defined two ways:
  1. TRADITIONAL (Skin) - Genuine vellum is a smooth and durable surface traditionally made from the hairless skin of very young calves or a calf foetus. 
  2. CONTEMPORARY (Paper) - Vellum is a term used by paper manufacturers to describe the surface of a PAPER (i.e. not skin). Modern "paper vellum" is synthesized from vegetable matter and is used for fine art paper, plans, technical drawings, and blueprints. 

Parchment and vellum are prepared skins which are NOT tanned.
...parchment in general refers to any type of animal skin turned into a paper-like material from physical action, including the removal of extraneous flesh, fat, and hair......
Here’s a simple formula: All vellum is parchment, but not all parchment is vellum.
Pergamena
In 2016, in the UK, there was scare relating to the production of vellum and parchment - summarised in this article The Great Vellum Scare - and what happened next. However vellum continues to be produced in the UK by William Cowley & Sons.

How is vellum sourced?
​

Vellum as a generic term is a surface derived from the skin of a calf.  

IMPORTANT points to note are:
  • No animals die to produce vellum.
  • Skins are typically sourced by ethical manufacturers from farms where livestock has been reared for wool, milk or meat.
  • ​Skins would otherwise be disposed of as waste products.
​

How is vellum made?
​

The photographs in this section are from a visit to William Cowley's in Newport Pagnell - organised by Shevaun Doherty and Dianne Sutherland, They show aspects of the process of processing skins from receipt to the completed end product.
'I think we're the only company in the world still making proper vellum in the proper way.' By this he means without harsh chemicals, completely by hand and 'pigging hard work'. ​The Last British Parchment Maker, WIlliam Cowley | House & Garden
Vellum is the skin of an animal which has been scraped of hair and flesh, cleaned, bleached and stretched on a frame.

Nothing much has changed about the traditional process over centuries of use - except how people dress!
Vellum and parchment making is a master craft
  • Vellum comes from calves, goats or deer. Parchment comes from sheep. 
  • Skins are first selected. Many are rejected due to faults in the skin e.g. scars
  • Next they need to be "rotted down". They are then defleshed by being soaked in vats containing lime and natural ingredients - a very smelly and dangerous process. This also also helps to loosen the roots of the hair!
  • Hair is then removed using a two handled scraper called a scudder. 'Skud' is an old English word for the removal of dirt, lime, fat, and fragments of hair from a hide / skins with the aid of a small knife. 
The purpose of the lime bath is to soften and dissolve the epidermal layer that lines the hair follicles thus making the hair easier to remove (Cains, 1992, p. 50)
Picture
Scudding - removing the hair from the skin after the skin has been soaked in the lime vat (seen in the background) c.1473 in Nuremberg
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At Cowley's - Shevaun Doherty tries her hand at removing the hair from a skin after it has been soaked in lime (At Cowleys in 2018)
  • Next a skin is tied with cords to a very robust frame - called a 'herse' - for further cleaning and stretching
  • The skin is then scraped, while still damp by a nam called a parchmentar. Imperfections like dark skin are scraped away. He uses a crescent-shaped 'half-lunar' knife (a "lunarium" or "lunellum" - lunar for short) to remove any remaining hair from the hair side and tissue from the flesh side and to stretch the skin to help it lie flat.  He needs two hands to scrape the surface in short, sharp bursts. (Ancient  vellum makers used flints).
  •  A little mark left on the skin can identify the parchment maker.
A 15th century parchment maker using a crescent-shaped scraper working a stretched skin clamped to a drying frame
A 15th century parchment maker using a crescent-shaped scraper working a stretched skin clamped to a drying frame. c. 1425 Nuremberg, Germany
Picture
After the hair has been removed, the skins are stretched on frames - which are tightened periodically and scraped - using the lunar tool (in his hand) to remove all traces of all hair and flesh. (At Cowleys in 2018)
  • When completely clean of all remnants of the animal, the skin is rinsed and stretched again to dry
  • Skins are then treated by being rubbed with pumice to make it smoother. 
  • A skin can be whitened and smoothed by washing it with with calcium carbonate (chalk). Applying chalk powder also makes it less porous. Chalk is also a component of gesso which is sometimes used to prepare the surface for painting.
  • Finally skins are cut to size - or left as whole skins and rolled.
A prepared skin has two sides:
  • The hair side is generally darker and smoother
  • The flesh side is generally whiter and softer.
Picture
Finished Rolls of Vellum at Cowley's (2018)
Rolls of vellum skins at Cowleys
Rolls of vellum skins at Cowleys
REFERENCE:
BIBLIOGRAPHY
The lime bath and mechanical dehairing in the preparation of parchment leaves the animal skins consisting almost entirely of collagen fibres. These fibres are composed of long chains of amino acids; mainly glycine, proline, hydroxyproline. Chemical bonds between these chains maintain the fibre structure and render it insoluble in cold water (Woods, 1995, p. 222).
This video is about a visit by the BBC to William Cowley & Sons and an explanation of how parchment is made.

It demonstrates
  • how skins are selected and kept in salt preserve,
  • lime washed to remove the hair on the outer skin,
  • how the skin is stretched and knives used to remove any tissue (fat etc) on the meat side;
  • how skins are stretched to dry in a warm environment.

​Vellum is essentially made in the same way.

Types of natural vellum
​

There are a variety of names for vellum - and these can vary between different places. Confusion over names goes back a long way.
That stouffe that we wrytte upon, and is made of beestis skynnes, is somtyme called parchement, somtyme velem, somtyme abortyve, somtyme membraan.
Vulgaria (1519) William Horman
Picture
Illustration of a German parchmenter from 1568
The word Vellum dates back to the 15th Century.
​The Old French "velin" means from velin of a calf, from veel (veal)

"Pergament" is an alternative name for parchment.
What makes vellum different from leather is that:
  1. the collagen fibres in vellum and parchment have a lower shrinkage temperature than collagen fibers from leather - and reduce when heated
  2. Vellum and parchment both soak up water rapidly and in greater amounts than leather.
  3. Wet vellum and parchment have a poor resistance to micro-organisms but is much more resistant if kept dry.
Below are the descriptions of different types of Vellum and Parchment. ​Each has its own unique characteristics.
  • ​Calf vellum is thicker and less translucent than parchment. The skin tends to be creamy and may have veins. It needs to be degreased using a very fine pumice in a fine mesh cloth prior to painting.​
  • Calfskin manuscript vellum - this type of vellum is typically prepared on both sides to make it suitable for use in books or any use where you want to paint on both sides. There are four grades of skins - from 1 - 4 - with 1 being fine (favoured by botanical painters and 4 being the coarsest.
  • Classic vellum is only bleached and prepared on one side. 
  • Natural vellum is not bleached and does not have a chalk wash surface. It is prepared on one side only. Consequently it is a natural (warmer, browner)  colour and also more transparent and slightly more shiny. You can also see the different characteristics of the skin of the animal eg venation. No two skins are absolutely alike.​
  • "Slunk" refers to the skin of an unborn, stillborn or prematurely born calf. The surface is very fine, lacks the flaws found in older calves and is translucent. Requires little or no preparation.
  • Kelmscott Finest Vellum - the name given to vellum prepared by William Cowley & Sons in the UK where the vellum surface is prepared with a specialist organic coating. It's made from the calf skin (or goat skin) and is prepared with a special plaster of paris surface wash to give a very smooth surface for painting or calligraphy - eliminating the markings on the skin. This makes it the heaviest of all the vellums. The coating also adds depth but does not diminish the luminosity of colour. Erasure is done via scraping the surface.
  • Goatskin vellum - the grain structure is more marked in this skin.
  • ​Parchment - for writing purposes - is traditionally derived from the skins of other animals - usually sheep or goat. 
REFERENCES:
“With most fraudsters, the moment they know a painting is on vellum they don’t bother trying to copy it. They know it’s a fruitless exercise. You might be able to skilfully copy the painting, but you can’t replicate the DNA of the material on which its painted. It’s unique.”  Artists turn to vellum to beat the forgers copying their work
Processed rolls of vellum and parchment
Processed rolls of vellum and parchment - each is individual and each has a unique DNA Photographed at William Cowley & Sons by Sarah Morrish

A video about vellum

A BBC Countryfile Video featuring Anita Rani and Gail Sellwood (Vice President of the Society of Botanical Artists). It includes a visit to William Cowley & Sons in Buckinghamshire - the only supplier of Vellum left in the UK
Picture
Study of Capers, Gorse, and a Beetle (1693) by Maria Sibylla Merian. Watercolor, white gouache, on vellum (sheet: 14 x 10 5/16 in. (35.5 x 26.2 cm) Collection: the Metropolitan Museum, New York
Three of the images of art on this page are from the Collection of the Metropolitan Museum of Art.
​Each image is linked to the page on the website which tells you more about the individual painting.
To find out more about Maria Sibylla Merian see her page in the History section of this website

​How to paint on Vellum - Including how to prepare vellum for painting

Today vellum is still used by both miniaturists and botanical artists who are painting in a very precise way - typically working with 'dry' watercolour using a stippling technique or very small strokes
The references (see below) give explanations about :
  • the nature of vellum and how it behaves
  • what it is like to paint on
  • how to prepare it for painting by using fine grade pumice to degrease and remove marks from vellum 
  • how to mount vellum on card or board
  • how to paint on vellum (see a summary of tips below)

Summary of Tips for Painting on Vellum
​

The following tips have been derived from reading every source I can find - online and off - about painting on vellum.

​See the end of this section for references to specific articles which include useful tips. As you might expect many repeat the same tips!
"If you've never painted on vellum before always start with Kelmscott."
Dianne Sutherland
Thickness of the surface
  • The thickness varies depending on which part of the skin is used. Skins are thicker along the spine and around the haunches and the neck. They're much thinner where they covered the ribs. Depending on how your skin has been cut it might include both think and thin skin. This is less of an issue for small works but is a factor which must be taken into account for larger works.
  • The thinnest vellum is Slunk - but it's still very strong when compared to paper

Sensitivity to humidity
  • vellum is very sensitive to environmental humidity levels - this can mean painting when humidity levels are low or painting in an air-conditioned environment
  • ​however if vellum is kept in a very dry environment the ink or paint will detach from the surface.,

Colour of surface
  • Very much a personal choice - do study the pictures of different kinds of vellum before you order your first vellum. You can also get samples from Cowleys.
  • Natural vellum has a creamier surface and Kelmscott has a whiter surface. 
Because of the nature of animal skin, parchment and vellum objects have acutely hygroscopic properties and are liable, even over a very short period of time, to unevenly change shape in all dimensions. 
Victoria and Albert Museum
How to stop distortion and bending
  • It's a skin - and it's not used to lying flat!
  • ​It has a natural tendency to bend and you need to counteract this. Thick vellum which has been rolled is going to need a lot of work to unbend the roll. 
  • Moisture helps to promote bending so avoid keeping vellum in any area where humidity is high.
  • Pergamena recommend keeping skins gently rolled up (head to tail - along the spine) in a stable @ 55% humidity environment. Then unroll and roll the other way before use.
  • Do NOT use heat to press flat.
  • Kelmscott is coated and therefore thicker than uncoated vellum and when unstretched does not tend to cockle as much
How to paint without distortion
  • Work small and keep it flat by placing under a heavy object (eg a book) when not working on it
  • buy vellum pre-stretched and mounted on supports. This is more expensive but eliminates concerns about distortion
  • Make vellum and parchment flat by mounting on a board to work - or more permanently ​. You can stretch the skin and mount it yourself (requires a lot of skill and is NOT for beginners) - see instructions (next)
  • work in harmony with the natural distortions in colour and natural skin; integrate these into compositions
Mount on a board
  • Use tape to stabilise the vellum as it can tend to bend with moisture in their air.
  • Tape the vellum to a more stable surface - such as card - prior to painting proper. This makes is easier to paint. Use a white card as you'll be able to see the colour of any support used through the skin and anything coloured may distort your view of the paint colours used.
  • You can actually stretch and mount vellum to a more rigid surface prior to painting. This tends to need an expert.
  • Materials used for mounting - boards, hinges, glues etc - need to be archival (i.e. non-acidic)

See technical REFERENCE section below
Picture
A Flowering Cactus: Heliocereus Speciosus by Pierre-Joseph Redouté (1759-1840) Watercolor on vellum, Framed- 27 5/8 x 22 1/2 x 3 1/4 in. (70.17 x 57.15 x 8.26 cm) LACMA Collection
Preparation
  • Any oil transferred to the surface will resist paint. Use a pounce pad to remove all oil and grease.
  • Make your own pounce pad using pounce or fine grade pumice (grade FFFF) in muslin / stockings or a 'footsie' in a circular motion to clean the surface and remove any sign of hair follicles, grease or marks
  • Also make sure you have removed all oil from your hands and forearms. Do NOT use hand cream prior to starting to paint! 
  • (see "Pumice" section below for explanation and retail and online suppliers) 
How to make a surface smooth again
  • Use pumice to resurface any vellum surface where there has been erasing. 
  • You can restore Kelmscott Vellum (vellum with a very smooth plaster of paris surface finish) by (1) scraping any marks off using the point of a scalpel or sharp knife and (2) smoothing the surface using an agate or bone folder 
Sarah Morrish paints a sequence of Samaras on vellum using watercolour and a Rosemary & Co Brush No.2
What Elizabeth Smith learned about painting on vellum in a workshop with Carol Woodin
Which side to work on
  • Work on the hair side (the side which once carried the animal's hair). The hair side is generally darker and smoother than the flesh side and some skins show speckled traces of hair follicles.
Drawing
  • Keep under-drawing in graphite to a minimum because it is difficult to erase it from vellum cleanly
  • Fine mechanical pencil leads tend to create the best result.
  • Use a small brush and a lightbox to outline in a pale paint​​​
Painting
​
This is NOT like painting on paper.  
  • Colours can glow on vellum and appear much more staurated than when the same paint is used on watercolour paper.
  • Vellum is not porous like paper - so water (and paint) sits on top of the vellum.
  • MINIMISE the use of water as this causes the vellum to cockle and lifts any paint already on the surface.
Painting techniques which do NOT work on vellum include: 
  • applying washes,
  • working wet-on-wet and
  • lifting off areas of colour with a brush and water to create highlights - however this works extremely well if you want to erase a whole area of paint back to the skin.​
​
What to do about mistakes
  • It's relatively easy to erase on Kelmscott because you can scrape the surface back to produce a clean surface
  • You can also use clean water to lift off the paint already applied - and get back to a clean surface! See the video below for a practical example of Shevaun Doherty demonstrating how to do this.
Techniques which work better include....
  • Work slowly and use patience and finesse
  • Use a brush that is damp rather than wet to paint using watercolour.
  • Use stippling and hatching rather than a wash.  If you push the paint around you will only lift any paint already on the surface. 
  • It's safer to paint around veins and highlights rather than lifting them out
  • Use staining pigments with great care as they will tend to sink into the skin and stain it - even when removed.
  • Use brushes for miniature painting to dot and dab - they reduce the scope for a brush to be too wet
  • when you have finished working on unmounted vellum, place it in a flat file and weight it down to stop it curling.
Picture
Pierre-Joseph Redouté, Still Life with Roses and Anemone, 1832. Watercolor on Vellum

Contemporary Tuition - Painting on Vellum
​

There's no exclusivity to 'painting on vellum'. Artists have been doing it for centuries. 

However a lot of contemporary practice has been relearned along the way - and some of it has been generously shared with others. ​Which is not to say you wouldn't benefit more by taking some lessons with those experienced in painting on vellum!
Botanical Painting on Vellum is now taught in a variety of ways.
See the see Education section on this website to find painting on vellum as

Practicing botanical artists who are tutors

Below is a list of those contemporary botanical artists who provide
  • tuition in painting vellum (or have provided in tuition in the recent past) and/or
  • have provided tuition in writing about painting on vellum.
UK & Ireland based tutors

Dianne Sutherland | Teaching website | Facebook Page
Without a doubt, Dianne Sutherland is the artist who has been most generous in sharing information and practices for painting on vellum. I very much recommend subscribing to her blog. 
  • HIGHLY RECOMMENDED - Notes on Painting Watercolour on Vellum (website under reconstruction)- by Dianne Sutherland. Includes notes on history of vellum, different types, preparation and how to paint on vellum. (I suspect this now forms part of her educational materials for students on her 'Botanical Painting on Vellum' course)
  • Dianne Sutherland: Painting on Vellum A blog post providing a comparison of Kelmscott and Natural Vellum. Plus tips on how to prepare it prior to painting
  • Day 13 and 14 Sidetracked by Vellum  by Dianne Sutherland focuses on mounting vellum prior to painting

Shevaun Doherty | Facebook Page
  • V is for Vellum - Shevaun Doherty (the new SBA tutor on painting on vellum) reviews the different kinds of Vellum
  • Seeking balance - a well illustrated step by step demonstration of painting on vellum by Shevaun Doherty
North American based tutors

Carol Woodin
  • occasional workshops (no teaching website)​

Kate Nessler
Denise Walser-Kolar | Workshops listed on website
  • Painting on Vellum - a detailed explanation of her personal approach with an exercise for those new to the surface

Karen Klugheim
Janine Walky
Below:
  • First Video: Sarah Morrish illustrates an overview of the various stages and techniques used when painting on vellum in a teaching video she prepared and used used for a course about painting on vellum.
  • Second Video: Shevaun Doherty demonstrates how to lift paint from vellum in a demonstration of how to paint on vellum

Historical references

REFERENCE: Historical Methods
REFERENCE: Historical Examples of painting on vellum

How to mount vellum
​

Mounted vellum
Mounted vellum in different sizes at the front. At the back you can see what vellum can do to boards which are NOT robust enough to withstand the skin wanting to curl!
Things you "Need to Know"
  • the skin wants to bend and curl and will not stay flat unless mounted to a solid support which will not bend
  • thinner vellum tends to distort more than ticker vellum
  • large pieces of vellum are more likely to distort than smaller pieces
  • the skin will not stay flat if high levels of moisture and humidity in the atmosphere can penetrate the mount / support / frame
  • hinging tape used for attaching unmounted vellum to a mat must be good quality and very reliable but might not be strong enough for the vellum curl
  • boards that vellum is stuck too can also distort under the pressure of the vellum wanting to curl (see the image above - the one at the back has started to curl).​ ​
More experienced vellum painters have developed different methods for mounting and framing vellum
  • artists tend to prefer to mount before they start work rather than after they have completed work
  • ​the support must be flat and dimensionally stable. Hence ensure that the support is structurally stable and cannot warp - particularly for larger pieces
  • Use an acid-free support (ie all the acidic tannins and lignins have been removed). Anything labelled suitable for archival or conservation by a reputable supplier should be OK.
  • A variety of adhesives have been used - they need to be acid free and archival. Some botanical artists have used rabbit glue; others have used PVA glue for sticking small vellum pieces to boards while others have used Liquid Pritt Sick as it is acid free
  • the method used for attaching the skin to the support depends on how the work will be displayed (eg will edges be on show or hidden behind a mat or a slip moulding).
The ampersand board will bend with the tension after glueing on anything other than small pieces so you need the cradled boards for larger pieces. The good thing about rabbit skin glue is that it’s reversible, so if there’s a bubble it can be flattened. If you use other glues it’s hard to correct
Dianne Sutherland (Discussion about Vellum in the Facebook Botanical Artists group)
REFERENCE: How to mount vellum for display
REFERENCE: People who can help you mount vellum

Specialists in Mounting Vellum
Museum Board
Various manufacturers produce museum boards - but you need to be careful of how they are made.
Conservation Adhesives

The conservation of vellum
​

Artists need to be very mindful of the archival materials and methods used for the mounting and framing of artwork on vellum - if their artwork is to enter a permanent collection and be preserved over time.
...acquisitions are generally perceived to be in good condition but, in some cases, a work of art that looks good in the frame proves to be mounted with materials likely to deteriorate in time.
The conservation of botanical illustrations on vellum: past, present and future (Kew)
Below are LINKS to articles, web pages and blog posts by those used to dealing with the conservation of vellum.
​
Because of the nature of animal skin, parchment and vellum objects have acutely hygroscopic properties and are liable, even over a very short period of time, to unevenly change shape in all dimensions.
The mounting of single leaf parchment & vellum objects for display and storage
The main research on the conservation of botanical illustrations on vellum has been summarised in a research paper published in 2013.

Key points are:
The physical damage and deterioration of vellums in the Collections at Kew appeared to be the result of three main factors:
  • inappropriate mounting techniques and inadequate storage enclosures - leading to warping, creases, tears and cockling
  • lack of environmental control or monitoring - changes in humidity causes vellum to change shape; and
  • poor handling techniques.

The vellums were remounted into 4-ply acid free mounts using a hinging method that would allow for some
expansion and contraction of the vellum.

The paper discusses:
  • Thread mount method
  • Vellum false margins
  • the use of microclimate frames (for exhibitions) incorporating conditioned Art-Sorb silica gel in sheet form
  • storage in Solander boxes on individual shelf units in an environmentally controlled area
Other conservation matters:
  • water and excessive moisture in the environment probably causes the most damage over time. It becomes susceptible to mold and mechanical damage
  • Micro-environments are considered to be less expensive ways to provide consistent storage environment
  • chemical treatments are ineffective in the cleaning of vellum and parchment​​
There are three primary concerns in the preservation of objects containing the protein collagen. The first is the immediate or short-term effects of the environment, primarily associated with temperature and relative humidity, on the physical properties such as strength, flexibility, permeability, and dimensional changes. The second is the long-term effects of the environment, associated with temperature, relative humidity, oxygen concentration, chemical pollutants, and radiant energy (light), in causing “aging,” or chemical modifications of the original material. Also important is how the environment allows biodeterioration by microorganisms and fungi of such a rich nutrient source.
The Effects Of Relative Humidity On Some Physical Properties Of Modern Vellum

REFERENCES: Museums and conservators

Conservation Products

The suppliers listed below are either those listed at the end of the research paper and/or are suppliers "By appointment to HM The Queen" Supplier of materials for conservation and preservation (Preservation Equipment Ltd)

Solander Boxes - for microclimate management Moisture ControlConservation Board

Suppliers of Vellum
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Picture
Four Tulips: Boter man (Butter Man), Joncker (Nobleman), Grote geplumaceerde (The Great Plumed One), and Voorwint (With the Wind) (ca. 1635–45) by Jacob Marrel. watercolor on vellum (sheet (c.): 13 3/8 x 17 11/16 in. (34 x 44.9 cm) Collection The Metropolitan Museum. Do read the narrative on the page about the image! (link embedded in image)
UK Manufacturer / Supplier

William Cowley is the main supplier of Vellum (and Parchment) in the UK and the the only commercial manufacturer of genuine Goatskin Vellum in the UK. They adopt an ethical approach to the the sourcing of raw materials and use environmentally sound production methods.

Based in Newport Pagnell, Cowleys can be contacted - quotes can be given and orders placed - via telephone or email (details on the website).

​Available products include: Ethical sourcing of raw materials | William Cowley
William Cowley strongly believe in environmentally sound business practices, including an ethical approach to sourcing raw materials and using 
UK Retailers

In practice suppliers buy their vellum direct from Cowleys. However if you don't want Kelmscott and prefer to select vellum personally you may prefer to deal with a retailer you can visit more easily.

Suppliers include
USA Suppliers

Talas is based in Brooklyn and their website has a shopping cart, It provides supplies and services to bookbinders and conservators in the main. They supply vellum from:
  • Cowley's - a useful summary description and images of the seven different types of calfskin vellum supplied by Cowley's
  • Israel
  • South America​
Pergamena, based in Montgomery NY, is a producer and supplier of parchment - which they describe as including vellum. They provide 2 day workshops in the production of vellum.
DO NOT BE MISLED by Paper Manufacturers who refer to their paper as "vellum". If it's paper it's not vellum - within the context of the subject on this page.
Brazilian Suppliers

​Cortume Runge (English website) Rua Coronel Seabra, 1165 - Santo André, São Paulo, Brazil 

Their animal parchment or Vellum comes from goat skins from the Northeast of Brazil  because they have less fat, providing a Pmore elaborate and high quality final product. 

Suppliers of Pumice
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Pumice Powder on a shelf in L. Cornelissen & Son
Pumice Powder on a shelf in L. Cornelissen & Son
Very fine grade "Pounce" (pumice powder and cuttlefish) or Pumice alone 60n/240 mesh is necessary for degreasing vellum in order to prepare it prior to painting.  

You can apply it using a small amount inside a muslin sack or make one for yourself out of a pop sock or stocking.

The amount of pumice released is dictated by how fine jade the pumice is and what denier the stocking (or tights) are.  The aim is to prepare the surface without causing any marks on it.
The various grades of pumice are defined as follows (and their typical uses are define in brackets). The mesh size relates to how many openings there are in one inch of a mesh sieve and measures the size of the largest particle.
  • Extra Coarse, 36 Mesh
  • Coarse, 1/0N grade / 60 Mesh Used for Dental Polishing and as Cosmetic Exfoliant)
  • Medium 2/0N grade / 90 Mesh (Used for Dental Polishing and as Cosmetic Exfoliant)
  • Fine 3/0N grade / 120 Mesh Used for Dental Polishing)
  • Superfine FF grade / 240 Mesh (Used for French and Metal Polishing)
  • Superfine FFF grade / 360 Mesh (Used for French and Metal Polishing)
  • Superfine FFFF grade / 360/90% Mesh (Used for French and Metal Polishing)
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UK Suppliers
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Also available online via Amazon UK
USA Suppliers
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Also available online via Amazon.com
Used for scrubbing, cleaning or polishing. Intended for use with hand buffs, brushes, felts and wood laps.