One line inside a square, and its direction is the whole instruction.
Look at which way the line runs. Vertical means hang the garment to dry. Horizontal means lay it flat. The difference matters most for knitwear, which stretches out of shape under its own weight when hung wet — and the two marks are otherwise identical, which is why the instruction is so easily misread.
A vertical line means hang to dry and a horizontal line means dry flat; the orientation of one stroke is the whole difference.
Drawn from the visual attributes recorded for each symbol. Only traits the two records disagree about are listed.
| Trait | Line dry symbol | Dry flat symbol |
|---|---|---|
| Symmetry | vertical | horizontal |
| Line dry symbol | Dry flat symbol | |
|---|---|---|
| Line direction | Vertical | Horizontal |
| Instruction | Hang to dry | Dry lying flat |
| Matters most for | Most garments | Knitwear, which stretches when hung |
| Base symbol | The drying square | The drying square |
| Relationship (from Symbolwise's records) | Commonly confused with Dry flat symbol — A vertical line means hang to dry and a horizontal line means dry flat; the orientation of one stroke is the whole difference. | Commonly confused with Line dry symbol — A horizontal line means dry flat and a vertical line means hang to dry. |
ISO 3758:2023, Textiles — Care labelling code using symbols
International Organization for Standardization · retrieved 2026-08-01
Paywalled and NOT READ. Registered so the standard can be named as existing and as defining the care-labelling system built on the five base symbols. It supports no individual record's specific meaning; those are carried by reference works that report them. See docs/paywalled-standards.md.
Wikipedia · retrieved 2026-08-01
Tertiary reference. Used for widely-agreed identity, origin and current use, not for contested detail or exact dates.