How much resin for an 18 × 24 canvas?

An 18 × 24 lands awkwardly on kit sizes: a full 1/8 in coat is about 30 fl oz before waste, so a 32 fl oz (1 quart) kit covers it only if almost nothing is lost to the cup or the edges. It’s a common size for posters, maps and larger acrylic pour paintings, which often have ridges and cells that drink a little extra.

What to know about an 18 × 24 canvas

Here the waste allowance, not the canvas, decides what you buy. With 5% extra the coat needs about 31.4 fl oz — one quart kit with barely half an ounce to spare. At 10% it tips over into a second kit (see the table). Your honest options: buy a quart plus a small top-up kit, buy a half gallon and plan a second piece for the leftover, or pour a thinner coat.

The thin-coat route is better than it sounds on a smooth print. At 1/16 in the coat needs about 16.5 fl oz, which leaves a quart kit with room for a second thin coat later. On a textured pour painting, though, a thin coat can leave the peaks bare.

The mistake to avoid is stretching the last few ounces. When you run short, it’s tempting to push the resin thinner toward the corners; a coat that’s too thin tends to pull back from the edges and corners and leave bare patches that need a second coat anyway. Mix what the calculator says in one batch — at about 33 fl oz it is still a manageable single cup — and pour it all.

One size down, how much resin for a 16x20 canvas still fits one quart. One size up, how much resin for a 24x36 canvas needs about twice this. If you work in metric, how much resin for a 50x70 cm canvas is the nearest European size.