Vellum and parchment on furniture

At a glance

RH is relative humidity. The humidity findings are from one 1992 study of three modern calfskin vellums (Hansen, Lee and Sobel); the rest of the table is our reading or an open question. Nothing here is a manufacturer's figure.

What vellum is, and what it is not

Parchment and leather are both made from animal skin, and both are dehaired by soaking and scraping. They part company there. Parchment is dried under tension, which aligns the fibre network more parallel to the surface; leather is tanned, which joins the fibres with chemical links. “Vellum” is the name for parchment made from the skin of young or unborn calves (Hansen, Lee and Sobel, 1992). A skin that has been tanned and one that has been dried under tension are different materials, so do not read leather guidance across: see our leather for furniture sheet for tanned hides.

The study the table is taken from also says that parchment has a lower shrinkage temperature than leather. It does not say what that means for a heated or lit furniture piece, and we do not guess.

Humidity: what the one study found

Hansen, Lee and Sobel tested three types of modern calf vellum. They pulled equilibrated samples to fracture, and they measured the force that built up in restrained samples when the relative humidity was stepped down between 60 and 11 per cent. Their findings, in the drawing: a level of 11 per cent hurt some tensile properties; about 25 per cent is the lowest level that can be tolerated without large stresses; more than 40 per cent increases gelation and the opportunity for biological growth; and 30 per cent seems the optimum, with a cyclic variation of 5 per cent either way giving minimal swelling and shrinkage.

Read it with three cautions the authors themselves give. The study aimed at the long-term preservation of collagen in documents; other aims, such as appearance or use, or the needs of other materials in a composite object, may set a different best condition. The commonest recommendation in the conservation literature is much higher, 50 to 65 per cent, and recommendations vary. And they report that no level could be excluded on tensile data alone. So treat 30 per cent as one defensible reference, not a specification for a table top.

What that means for a real room

We found no source that gives the humidity inside a heated London flat, a hotel bedroom or a restaurant, and none that links the study's figures to furniture. So the practical step is to find out. Ask the client or the building services engineer for the logged relative humidity of the room through a winter and a summer, and for the bathroom or kitchen next door if there is one. Then write the range you expect, and the fastest swing, into the specification, and ask the partner workshop to confirm in writing that vellum suits it.

• Steady beats ideal. The study allows 5 per cent either way at its best level. A room that swings by far more than that is a harder home than one held a little off the optimum.
• Heating and glazing. Rooms that are heated hard in winter, or that sit in direct sun, are the ones to log first. We have no figure for how far they dry.
• Wet areas. Above 40 per cent the study found more gelation and more opportunity for growth, and the skin takes up water quickly. Keep it away from splash, steam and wet cleaning.

How the skin is held

The measured force in a restrained sample is the reason the way a skin is held matters. A skin stuck to a rigid backing across its whole face, one clamped at its edges in a frame, and one fixed at the middle with its edges left free are three different cases. The drawing is a concept: we have no source for allowances, gaps or adhesives, and which method suits a piece is for the partner workshop to say, with the reason.

Ask for a sample panel built the way the piece will be built, conditioned over the range you have logged, and kept as the reference for acceptance. Our timber movement in panelling and veneer sheet covers the backing, and prototype and mock-up approval covers the sign-off.

Finish, light and care

The study sets light and pollutants aside, and no source we read gives a sealing system, a colour-fastness result or a stain test for vellum on furniture. So these are questions, not answers:

• What seals the surface, and has it been tested on offcuts of the same skin for a water ring, a wax mark, a greasy finger mark and light?
• How much will the colour vary between skins on one piece, and can a sample show the range?
• Written care instructions for the client, and who repairs a damaged skin.
• For a hanging or lit piece, the heat the skin will see: see our lamping glass lighting sheet for the lamp side.

Where the skin is a veneer on a table or a cabinet top, the finish rules on our finishes on timber joinery sheet are a starting point only: a skin and a timber do not take a finish the same way.

Where to use it

Our judgement, not a sourced rule: vellum suits surfaces that are looked at more than touched, in rooms where humidity is steady and measured.

Vellum (calf parchment) panel to ref [V-01], size [ ] x [ ] mm, skin thickness [ ] mm to be stated by the maker, held by [method to be proposed by the maker with reason]. Design relative humidity range for the room [ ] to [ ] % RH, greatest expected change [ ] % RH in [ ] hours, from logged data supplied by [ ]. The maker is to confirm in writing that the proposed build suits that range before samples are made.

A sample panel of [300 x 300] mm built exactly as the production piece (same skin type, backing, adhesive, holding method and seal) is to be conditioned over [ ] to [ ] % RH for [ ] weeks and photographed before and after. The approved sample is retained by [ ] as the acceptance reference. Colour range across skins shown on [ ] skins.

Sealing system [ ] to be named by the maker with test results on offcuts for water, wax, grease and light exposure [ ]. Written care and repair instructions to be supplied with the piece. Not to be used within [ ] mm of a basin, hob or shower unless the maker confirms in writing.

Standards and sources

• Hansen, Lee and Sobel, The effects of relative humidity on some physical properties of modern vellum, JAIC 31(3), 1992, pp. 325 to 342: all figures on this sheet. Read 7 Nov 2026 (web edition, abstract and sections 1 to 2.2).
• No British Standard for vellum on furniture was identified: none was found in the sources read; do not assume one exists.

Questions we are asked

Is vellum the same as parchment?

Vellum is a kind of parchment: the name for parchment made from the skin of young or unborn calves. Both are dried under tension, not tanned, which is why they behave differently from leather.

What humidity does vellum need?

One 1992 study of modern calf vellum found about 30 per cent relative humidity best for the material, with a 5 per cent swing either way tolerated, large stresses below about 25 per cent, and more gelation and biological growth above 40 per cent. The commonest recommendation in the conservation literature is 50 to 65 per cent, and recommendations vary. It was a study of documents, not furniture.

Will vellum cope with central heating?

We found no source that answers this. Ask for the logged humidity of the room across a winter, and ask the workshop to confirm in writing that the build suits that range, with a sample conditioned over it.

Can I use vellum on a table top?

It is the harshest use, because of contact, cups and cleaning. No source we read gives test results for a sealed vellum top. Ask for water, wax, grease and light tests on offcuts of the same skin before you specify it.

How big can a vellum panel be?

We found no source that gives a skin size or a panel limit. Ask the partner workshop for the largest single skin, where joins fall and how they are made, and show them on the drawing.