What to use when the recipe calls for something you don't have. Most are honest equivalents, a few are compromises — the notes column says which.
| Original | Swap In | Trade-off |
|---|---|---|
| Gum arabic (binder) | Honey + a pinch of flour paste; cherry-tree sap; PVA glue thinned 1:5 | Gum arabic is water-soluble, archival, and re-wets — substitutes lose one or more of those. |
| Iron sulfate (mordant) | Rusty nails soaked in white vinegar 2 weeks | Same active compound, slower to dissolve. Strain before use. |
| Linseed oil | Walnut, poppy, or safflower oil — all oxidize and dry | Linseed dries fastest and yellows most. Walnut yellows least. |
| Methyl cellulose | Wallpaper paste, cooked corn starch, or rice paste | All form a non-staining, reversible glue. |
| Rabbit-skin glue | Plain unflavored gelatin (slightly weaker), or PVA + water 1:4 | Real RSG is the most flexible; gelatin embrittles in low humidity. |
| Etching ink | Stiff oil paint + a few drops of linseed oil + a spoon of cornstarch | Won't be archival but prints fine for proofs. |
| Lampblack pigment | Soot from any oil flame, or laser-printer toner (toxic — wear gloves) | Free, jet-black, lightfast. |
| Mould & deckle | Two thrift-store picture frames + window screen | Identical results. See the equipment section. |
| Brayer / roller | Hardware-store mini foam paint roller | Wrap with tape for a firmer surface. |
| Etching needle | Empty ballpoint pen, large nail, dental pick | Sharper = finer line. |
| Litho stone | Aluminum soda-can or kitchen foil + cola etch | Not as long-lived but functions identically. |
| Acrylic gesso | Equal parts PVA glue, chalk powder, and water + a squirt of white acrylic | Cheaper, slightly less opaque — apply 4 coats instead of 3. |
| Watercolor paper | Hot-pressed cardstock sized with diluted PVA + alum | Won't take heavy washes but fine for sketching. |
| Drying rack | Window screen across two stacks of books | Air must reach both sides of every sheet. |
| Press blanket / felt | Old wool sweater, blanket, or cotton bath towel | Anything thick, soft, and lint-free. |
| Distilled water (ink-making) | Boiled-and-cooled rainwater | Both are mineral-free and won't react with iron salts. |