How to frame a picture

Framing at home is not difficult. It is a sequence, and doing it in the right order — with clean hands and a clean surface — produces a result indistinguishable from a shop's for most work.

What you need

• The frame, with its glazing and backing
• A mat, if you are using one
• Photo corners or archival hinging tape
• A microfibre cloth and glazing cleaner
• A soft clean surface to work on — a towel or a sheet of foam board
• Cotton gloves, if the artwork is valuable
• Gummed paper tape for sealing the back

Set up somewhere with as little dust in the air as possible. Not a workshop, not immediately after vacuuming.

Step 1: open the frame

Lay the frame face down on the soft surface.

Ready-made frames close in one of three ways. Flexible metal points driven into the rabbet, which bend outward with a fingernail or a flat screwdriver. Turn buttons, which rotate ninety degrees. Stapled hardboard, on the cheapest frames, which has to be prised out and cannot be reused neatly.

Lift the backing board out, then the mat if there is one, then the glazing. Keep everything in order and the right way up — the mat has a front and a back, and its bevel only looks right one way round.

Step 2: clean the glazing

Do this properly because it is the one thing you cannot fix later without dismantling everything.

Spray the cloth, never the glazing. Liquid sprayed at a sheet held in a frame runs into the rabbet and onto the mat.

For glass: a microfibre cloth lightly dampened with water handles most of it; a drop of isopropyl alcohol deals with fingerprints. Clean both faces.

For acrylic: use a dedicated plastic cleaner or plain water. Never use ammonia-based glass cleaner, which crazes acrylic permanently. Remove the protective film from both sides only at this point, and expect the acrylic to attract dust electrostatically — an anti-static cleaner is worth having.

Hold the sheet up to a light at an angle to check for smears before you go further.

Step 3: mount the artwork

The artwork attaches to the backing board, not to the mat and not to the glazing.

Photo corners are the simplest method and the safest. Four small transparent or archival pockets stuck to the backing board, into which the artwork's corners slide. No adhesive ever touches the artwork, and the whole thing is completely reversible.

Hinging is the method for artwork that will show its own edges, or that is too large for corners to hold. Two small hinges of archival tissue or hinging tape are attached to the top edge only, so the artwork hangs from the top and is free to expand and contract with humidity.

The rule that matters: never attach all four edges. Paper moves with humidity. Fixed on all sides, it has nowhere to go and buckles — the ripple you see in badly framed prints is almost always this.

Things never to use: ordinary sticky tape, masking tape, glue stick, spray adhesive, or dry mounting on anything with any value. All of them yellow, harden, and stain through the paper within a few years.

Step 4: position it squarely

Place the mat over the artwork and look at the borders on all four sides.

Measure them. Do not judge by eye — an eighth of an inch of misalignment is clearly visible in the finished frame and completely invisible while you are looking down at it on a table.

Adjust the artwork until the borders are even, or until they match the deliberate weighting if the mat is bottom-weighted. Then secure the corners or hinges properly.

If the mat opening itself is off-centre — which happens with cheap ready-made mats — centre the artwork within the opening rather than within the mat, and accept the mat's error. The eye reads the relationship between image and opening far more strongly than the relationship between opening and frame.

Step 5: assemble in order

Front to back:

1. Glazing
2. Mat (or spacers, if no mat)
3. Artwork, attached to the backing board
4. Backing board
5. Optional dust cover of thin card

If you are not using a mat, add clear spacers — thin plastic strips that sit in the rabbet and hold the glazing a fraction of an inch off the artwork. Paper pressed directly against glazing will eventually bond to it in humid conditions, and separating them without damage is a conservation job.

Before closing, hold the assembled stack up to the light and check for dust or hairs between the glazing and the artwork. A small rubber bulb blower removes them without contact. This is the last moment it is easy.

Step 6: close and secure

Fit the retaining points or turn buttons. Points should press the stack firmly enough that nothing rattles, and not so hard that the backing bows.

If the frame originally had stapled hardboard, replace it with flexible points — they are sold cheaply, they fit any frame, and they make the frame openable in future.

Step 7: seal the back

Run gummed paper tape or acid-free framing tape around the join between the backing board and the frame, covering the gap completely.

This is not cosmetic. The seal keeps dust and, more importantly, insects out — silverfish will eat paper inside an unsealed frame and you will not know until you open it. It also stabilises the internal humidity.

Step 8: fit the hanging hardware

D-rings a third of the way down from the top on each side, wire between them with a couple of inches of slack. Felt bumpers on the bottom rear corners.

For frames above 16x20, use two wall hooks rather than one. Full details of fixings by weight are in the hanging guide.

The mistakes that cause the most regret

Taping all four edges. Causes buckling within months.

Ordinary tape on artwork. Yellows, hardens, and stains through.

Artwork touching glazing. Bonds permanently in humid conditions.

Trimming artwork to fit. Irreversible, and the cut edge always shows.

Positioning by eye. Measure the borders. Always.

Not sealing the back. Dust and insects, both entirely preventable.