A4 measures 21 × 29.7 cm. We carry it, listed as 21×30, and the three millimetres of rounding on the height vanish under the frame's rebate. An A4 print and our 21×30 frame are the same thing. What is worth spending words on is not the conversion but the decision: this is the smallest format we make, and it is right far less often than people expect.
How small 21×30 really is
Sizes on a screen all look reasonable. Set against the other four formats by area, the scale becomes obvious.
| Format | Area | Times a 21×30 |
|---|---|---|
| 21×30 | 630 cm² | 1× |
| 30×42 | 1,260 cm² | 2× |
| 50×70 | 3,500 cm² | 5.6× |
| 70×100 | 7,000 cm² | 11× |
| 100×140 | 14,000 cm² | 22× |
A single 21×30 on an empty living-room wall is a stamp. The exact millimetres for all five, and how they line up against the A series, are in the poster size guide.
When 21×30 is the right size
It works where you are close to it and where the wall is small. A cloakroom or a small bathroom, where you stand within a metre of the wall and there is a metre of tiling below it. Beside a light switch or a door frame, in the 40 cm of plaster that nothing else fits. At a desk, at seated eye level. In a child's room hung low, where a small frame at a child's height beats a large one they have to look up at. Short texts and single words also survive the reduction better than detailed images, which is why quote prints and small formats go together.
Coco Chanel perfume poster
Black COCO poster
Coco Chanel perfume pink poster
William Morris contenary exhibition poster
William Morris birds poster
Bubblegum giraffe poster
In numbers, in a row
The other real use is as a building block. Several 21×30 together reach a span a single one never will.
| Arrangement | Gap | Total span | Total height |
|---|---|---|---|
| Two in a row | 4 cm | 46 cm | 30 cm |
| Three in a row | 4 cm | 71 cm | 30 cm |
| Five in a row | 4 cm | 121 cm | 30 cm |
| Grid, 2 × 2 | 4 cm | 46 cm | 64 cm |
| Grid, 3 × 3 | 4 cm | 71 cm | 94 cm |
A 3 × 3 grid of 21×30 covers 71 × 94 cm, which is almost exactly the footprint of a single 70×100 — built from nine frames, nine hooks and eighteen measurements instead of one. That is the trade. If you want the block, buy the block; if you want the rhythm of nine images, the grid earns the extra work. Both are laid out with figures in the gallery wall layouts.
When it is too small — say it plainly
Above a sofa or a bed, alone, never. Two thirds of a 160 cm bed is 107 cm; a 21×30 gives you 21. Even five in a row reach 121 cm at only 30 cm tall, which above a bed reads as a strip rather than a piece of art. In a hallway, one 21×30 on a long wall disappears at walking pace. And on any wall above 200 cm of clear plaster, a small frame does not look modest — it looks like a placeholder for the right one.
Practical notes
21×30 comes in oak, black and all seven colours, since the coloured finishes run up to 50×70. It is light enough to hang on a single small fixing, which is part of why it suits a child's room and rooms where things get rearranged. In a wet room, keep it clear of the shower spray and off the wall directly behind a basin tap — the format suits a bathroom, the damp does not suit the paper.