Shadow box mounting: pins, stitches, wire and what to avoid

The safest way to mount anything in a shadow box is to hold it, not stick it. Stitch fabric, tuck paper into corners, rest heavy things on a ledge and tie them back, and keep glue for the parts of the box that are not the keepsake. Museums work this way because each of those fixings can be undone later without harming the object.

This guide goes through each method, the supplies it needs, and what the conservation bodies say about the short cuts. The rules and the quotations come from those bodies. The ways of applying them inside a small box at home, such as ledges, ties and pins left in place, are practical advice built on those rules, not published museum methods. For building the box and laying things out, see how to make a shadow box.

The rule museums follow

The Canadian Conservation Institute (CCI), an agency of the Canadian government, puts it plainly in its bulletin Products Used in Preventive Conservation: “Applying adhesives or tapes directly to objects is unsafe and not recommended. Over time, adhesive on an object can become brittle or viscous, suffer bond failure and cause staining”. Adhesives “should be used only for assembling storage and display fittings, such as mounts, backings, boxes, sleeves and cases”. And of tape: “It can be assumed that all tapes will fail to adhere one day; it is just a question of time.”

So the question for each object is: what holds it mechanically?

Object	Hold it with	Keep away from it
Photographs, tickets, letters, certificates	Photo corners, mounting strips, paper hinges	Sticky tape, glue stick, spray mount
Clothing, ribbons, embroidery, lace	Stitches into a fabric-covered board; pins between the threads	Glue, tape, staples, tacks
Medals, coins, badges, keys	Their own pins and clasps; padded loops of thread	Glue, bare brass wire, PVC
Leather: collars, gloves, shoes	Ties of cotton tape; a ledge and a shaped support	Sharp folds, glue, dressings
Heavy things: a mug, a horseshoe, a ball	A ledge that carries the weight, plus a padded tie	Glue alone, thin line alone
Shells, stones, glazed china	A ledge, a cradle of bent acrylic, or a tie	Putty on anything porous

The backing comes first

Everything is fixed to the backing board, so the board has to be safe to touch and able to take a needle.

The board. CCI’s note on framing textiles lists acid-free matboard, corrugated plastic board and acid-free foam board as acceptable, and “unsealed wood and wood products such as Masonite” as unacceptable in contact with textiles. Its products bulletin adds that rigid PVC foam boards “are not recommended for use in contact with objects”.
The covering. “Cotton, linen and polyester are safe products to use with objects.” Wash the fabric first: CCI’s method is one machine wash, then two cycles with no detergent, to take out the sizing. Test coloured fabric for dye that runs.
Wool felt and silver. Wool can give off sulphur gases. CCI’s view is that “only when wool is almost touching sensitive metals, such as silver, is there a cause for concern”. For silver medals and jewellery, choose cotton velvet or polyester felt.
Glue on the board, not the keepsake. Wrap the fabric round the board and glue it at the back only. CCI allows white glue there, kept “away from the edges and the front of the support”, and asks you to “allow time for the white glue to cure and off-gas completely” before sealing the frame. Its bulletin gives three to four weeks for adhesives used inside an enclosure.

Paper and photographs

The Library of Congress’s guidelines for matting and framing ask for “non-adhesive hinging (e.g., photo/mounting corners; polyethylene strapping; mounting strips) whenever possible”, or “Japanese tissue hinges applied with refined wheat starch paste”.

Photo corners are small pockets fixed to the board. The photograph slides in and nothing sticks to it.
Mounting strips hold the edges of a sheet under a lip in the same way.
Hinges are small paper tabs pasted to the top edge of the back. Starch paste is used because, in CCI’s words, it is “removable if necessary (by a trained conservator)” and does not stain.

For anything irreplaceable, frame a copy and keep the original in the dark. The Library of Congress says of paper that “light exposure causes permanent damage” and that the best alternative to long display is “to mat and frame a well made reproduction”.

Fabric and clothing

Stitching is the museum method, described step by step in CCI’s note on mounting small, light, flat textiles.

Lay the piece on the covered board and pin it round the edge to hold its place. “Insert the pins between the threads in the textile instead of through them.”
With a fine needle and colourfast thread, stitch the edge to the covering fabric, taking out the pins as you go.
Add lines of small stitches across large plain areas, so that the weight is shared and nothing sags when the board stands upright. “Use a small, almost invisible stitch on the surface of the textile and a longer stitch through the fabric covering the support.”

CCI’s note on stitches adds three habits: “use as few stitches as possible”, “stitch through existing holes and avoid piercing the threads”, and keep the stitching relaxed, because tension “can break old threads”. Use cotton or polyester-and-cotton thread: the note warns that synthetic threads “are generally too strong and may damage a fragile textile”.

Mounting pins

Pins are quicker than stitches, but leaving them in is a short cut and not CCI’s method. Its note uses pins only to hold a textile in place while it is stitched (“Remove the pins as the stitching proceeds”), and its framing note lists “staples, tacks, nails” among the things that should never touch a textile. For anything old, fragile or irreplaceable, stitch. For a modern piece in sound condition, pins are a practical compromise. The three rules below are our advice, drawn from what those notes say goes wrong:

Go through seams, hems and gaps in the weave, never through a thread, a ribbon’s face or a signature. This follows CCI’s rule for its positioning pins, which go between the threads.
Use pins that resist rust. CCI’s framing note records what happened to old samplers held by metal tacks: “staining as the metal tacks corroded”. CCI names no pin for the job; stainless steel is the practical choice.
Use enough of them. The same note says tacks “spaced at intervals” made “holes and uneven tension”. A pin every few centimetres along a seam spreads the load. Two pins at the shoulders make two points that stretch.

Angle each pin downwards into the foam board, like a picture hook, so the weight pulls it in.

How to secure heavy items

Weight needs something underneath it. A tie only stops the object tipping forward. CCI’s bulletin gives the rules for line and padding quoted below; the ledge and the tie through the backing are a practical way to follow them in a shadow box, not a mount taken from CCI. Take anything valuable or fragile to a framer or a conservator.

Give it a ledge. A strip of sealed wood or acrylic, fixed through the backing into the rigid back of the box, carries the weight. For a ball or a mug, a ring or a shallow hollow stops it rolling.
Tie it back. Pass a line round the object and through two holes in the backing, and knot it behind. CCI’s rule for line: “a breaking strength of at least 10 times the weight of the object (e.g. use at least a 5-kg-strength string for a 0.5 kg object), and the line should be changed after 10 years.”
Pad the line. CCI warns that lines and strings “can also cut into softer surfaces”, and names wood, plaster, paints and finishes, other plastics and leather among them. It pads the points of contact with thin polyethylene or silicone tubing slipped over the line.
Fix to the box, not the foam. Foam board holds a pin. It does not hold a kilogram. Take ties and screws through to the plywood or hardboard back.
Hang the box to match. The Fine Art Trade Guild’s advice is two hooks on the wall, “each set about a quarter of the way in from either side”, with a cord or hanger “designed to support the weight”.

Metal against metal needs thought too. CCI lists bare “brass rods and strips commonly used for mounts” as a corrosion risk, in damp conditions, to objects made of less noble metals such as zinc, aluminium, lead or iron. Cover any wire or clip with tubing where it touches.

Glue, putty and tape: where each stands

Hot glue. CCI’s bulletin says hot-melt glue avoids the drying time other adhesives need, and its example of a short list of products known to be safe has “hot-melt glues (colourless) used with hot-melt glue gun, not applied to objects”. Colourless sticks are preferred because they contain no rosin or sulphur compounds. Use it to build ledges and cradles, not on the keepsake.
Silicone. The common kind that smells of vinegar “releases a substantial amount of acetic acid during curing” and “should not be used inside enclosures”. CCI calls neutral cure silicone “a much better alternative”, and even then lets it air for a few weeks.
Museum putty and gel. A short- to medium-term hold for “waterproof and smooth surfaces such as glass, metal or coated metal”. It is “not suitable for many types of porous objects such as wood, fabrics, unglazed ceramics, stone”, because the oil in it stains, and it loses its grip as it ages. CCI describes it pressed under an object that stands on a level surface, to steady it against knocks. In a shadow box that means under something standing on a ledge, not behind something on the upright backing.
Double-sided tape and foam pads. Fine for card mounts, labels and paper scenery you made yourself. On a keepsake they are tape, and tape fails.

If the thing is not precious, such as a bought shell or a spare button, glue is a fair choice. Decide object by object.

Keep everything off the glass

Nothing should touch the glazing. The Library of Congress asks framers to “ensure the object does not touch the glazing”, and CCI explains why: a gap stops raised parts being crushed and “reduces the risk of moisture condensing on the glazing” against the object. Allow about 10 mm between the thickest thing and the glass.

A paper backdrop and a name plate

Scenery you cut yourself can be glued freely, since it is not the keepsake. A layered skyline or forest from the shadow box maker makes a backdrop behind tickets or a medal: download the sheets, cut them from card and fix them to the backing before anything else goes in. For a name, a date or a place, Text to SVG turns the words into outlines sized in millimetres for a cutting machine. Both are decoration; neither holds anything up.

A shopping list

Acid-free foam board or matboard for the backing
Washed cotton, linen or polyester fabric to cover it
White glue, for the back of the board only
Stainless steel pins; a fine needle and cotton thread
Photo corners or mounting strips
Nylon or polyester line rated at ten times the heaviest object, and thin tubing to pad it
Strips of acrylic or sealed wood for ledges
Clean cotton gloves for handling metal