Framing works on paper so they last

A painting on canvas can more or less look after itself on a wall. A work on paper cannot. Paper is made of fibres that drink in moisture, yellow in sunlight, stain from acidic neighbours and cockle when the weather turns. A drawing that has been framed badly can be ruined in a decade, slowly and quietly, behind the glass. A drawing that has been framed well can look much the same in fifty years as it did the day you bought it.

The good news is that conservation framing is not mysterious. It is a set of fairly simple choices, made in the right order, with materials that will not harm the work. This piece runs through each part of the frame, from the front glass to the back board, so that you can talk to your framer as an equal and know what you are paying for.

Why paper needs special care

Most of the damage done to works on paper comes from four things: acid, light, moisture and adhesive. Acid migrates from cheap board and old wood into the paper, leaving brown lines and spots. Light, especially ultraviolet, fades pigments and yellows paper. Moisture and swings in humidity cause rippling and encourage mould. And adhesives, above all pressure-sensitive tapes, stain and become impossible to remove.

Conservation framing deals with each of these by keeping the work in contact only with stable, acid-free materials, filtering the light, leaving the paper free to move and using adhesives that can be undone.

The mat

The mat (or mount) is the board with a window cut in it that sits between the work and the glazing. It does two jobs: it frames the image visually, and it holds the glazing away from the surface of the paper.

For anything you care about, the mat should be made of acid-free conservation board. The best is 100 per cent cotton rag board, sometimes sold as museum board, which is naturally free of the lignin that turns wood-pulp board yellow. Purified wood-pulp conservation board is a sound, more affordable alternative. What you want to avoid is ordinary decorative board with a coloured paper face and a pale core that turns brown, because over time it can leave a stain on the work around the window. Framers call this mat burn, and once you have seen it on an old print you will check every frame you own.

The backing mat, behind the work, should be the same quality as the window mat. Together the two boards form a protective folder for the paper.

Hinging: how the paper is held

This is where good framing and bad framing part company. The work should be attached to the backing mat with small hinges of Japanese paper and wheat starch paste. Japanese tissue is thin but strong, with long fibres. Wheat starch paste is a conservator's adhesive that holds well and can be released later with a little moisture, without harming the work.

Hinges go only along the top edge, so the sheet hangs from them like a curtain and can expand and contract with the weather. Fixing all four sides, or gluing the whole back down, traps the paper and leads to buckling. A common method is the T-hinge, where one strip is pasted to the back of the work and a cross-strip holds it to the backing board. If the work is to float, showing its edges, the hinges are hidden behind it.

Why never tape

Masking tape, sticky tape, double-sided tape and most "acid-free" self-adhesive tapes have no place touching a work on paper. Their adhesives yellow, creep into the fibres and harden. Removing them later is slow, specialist work, and often leaves a permanent mark. If you have an old print stuck down with yellowing tape, do not try to peel it off yourself. Take it to a paper conservator. The Australian Institute for the Conservation of Cultural Material (AICCM) keeps a directory of conservators and is a good place to start.

Dry mounting, where the work is heat-bonded flat to a board, should also be avoided for original works on paper. It is effectively permanent.

Glazing

Glazing is the clear sheet at the front. The choices are glass or acrylic, and both come in plain and UV-filtering versions, with or without an anti-reflective coating.

Glazing	Strengths	Drawbacks	Good for
Plain glass	Inexpensive, scratch resistant, clear	Heavy, breakable, little UV protection	Inexpensive posters in low light
UV-filtering glass	Blocks most ultraviolet, scratch resistant	Heavier and dearer than plain glass	Most prints, drawings and watercolours
Anti-reflective UV glass (often called museum glass)	Almost invisible, strong UV protection	The most expensive option	Works you look at closely, in bright rooms
Acrylic	Light, shatter resistant, UV versions available	Scratches easily, holds static	Large works, hallways, children's rooms, works that travel

There is one important exception to acrylic: pastel, charcoal and soft chalk. Acrylic builds up static, which can lift loose pigment off the paper and onto the inside of the glazing. For these, use glass.

UV-filtering glazing slows fading but does not stop it. Visible light fades pigments too, so a watercolour should still hang out of direct sun.

Spacers and depth

The glazing must never touch the surface of the work. A window mat usually provides enough gap, but if you want the work floated without a mat, or the work is especially delicate, the framer will fit spacers: thin strips hidden inside the rebate of the frame that hold the glass away.

Spacers matter most for pastel, charcoal and soft graphite, which can smudge onto the glazing, and for thick or cockled paper that would otherwise press against it. Ask for a slightly deeper frame if you think the paper will move.

The backing

Behind the backing mat goes a rigid board that supports everything. Acid-free foam board or corrugated polypropylene are common choices. Ordinary hardboard, MDF and cardboard should not be used directly behind the work, because they give off acids over time. If an old frame has a hardboard back, a barrier of acid-free board between it and the work is the minimum.

The back of the frame is then sealed with a dust cover of paper and framer's tape around the frame edge (tape on the frame is fine; tape on the art is not). Small bumpers on the lower corners let air move behind the frame and keep it from marking the wall.

A worked example: a print of 38 by 28 centimetres

Say you have bought an etching on a sheet 38 centimetres high and 28 wide, with a plate mark about 30 by 20. Here is how a sound frame might come together.

1. Mat: cotton rag board, with a window cut a few millimetres outside the plate mark so the margins and the pencilled edition number and signature show. Mat borders of about 7 centimetres at the sides and top, and a little more at the bottom (perhaps 8), which looks balanced to the eye.
2. Outside size: a window of about 31 by 21 centimetres plus those borders gives a mat of about 46 by 35, comfortably larger than the sheet itself, so the frame is made to fit a mat of that size.
3. Hinges: two T-hinges of Japanese tissue and wheat starch paste along the top edge of the sheet.
4. Glazing: UV-filtering glass, since the etching ink and paper benefit from it and the hallway gets afternoon light.
5. Backing: acid-free foam board, then a sealed paper dust cover and wall bumpers.

The framer will tell you if your print would look better floated, or with wider borders. Listen; they have seen thousands.

What to ask your framer

• Are all the boards that touch the work acid-free, and is the window mat cotton rag?
• How will the work be hinged, and with what adhesive?
• Will anything adhesive touch the front or back of the work, other than the hinges?
• What glazing do you suggest for this work and this room, and why?
• Is the glazing clear of the surface, and will you use spacers?
• What goes behind the backing mat?

A good framer will welcome these questions. If a framer brushes them aside, take your drawing somewhere else. When I bought my first decent print I learned more from twenty minutes with a framer than from any book, a point that sits well with the advice in buying your first original artwork about holding back part of your budget for the frame.

Works that deserve it

Conservation framing is worth it for anything original: drawings, watercolours, gouaches, prints in editions and photographs. Many painters make works on paper alongside their canvases, and those are often the most affordable way to own their work. John Olsen, for instance, made a great many drawings and works in watercolour and ink over his long life, and anyone lucky enough to own one should frame it with care; our essay on John Olsen looks at his restless line. Philip Hunter is another painter who also works as a printmaker and draughtsman, and our note on Philip Hunter is a good reminder of how much happens on paper in an artist's practice.

Look after the paper, and it will look after itself for a very long time.