Before modern standardisation, British printers specified many sheet sizes by trade names. The British Association of Paper Historians records the values below as a guide, so they are best used to identify historical work rather than to order contemporary paper. Dimensions are given in the source’s inches, with rounded millimetre conversions alongside.
| Sheet name | Dimensions (in) | Approx. dimensions (mm) |
|---|---|---|
| Crown | 16¼ × 21 | 413 × 533 |
| Demy | 17¾ × 22½ | 451 × 572 |
| Medium | 18¼ × 23 | 464 × 584 |
| Royal | 20 × 25 | 508 × 635 |
| Super royal | 21 × 27 | 533 × 686 |
| Double pott | 15 × 25 | 381 × 635 |
| Double foolscap | 17 × 27 | 432 × 686 |
| Double crown | 20 × 30 | 508 × 762 |
| Double demy | 22½ × 35½ | 572 × 902 |
The same name can indicate a different size in another paper class—for example, writing paper or board—so preserve the material context when cataloguing a sheet. For current press work, use the printer’s specified stock or an ISO press-sheet format. Source: British Association of Paper Historians, “Old English Paper Sizes”.