the fabric and cut plan
Cut on the repeat
Before the shears go in, the length is worked out.
This page does the arithmetic that comes before any cut: how many widths a heading needs, how long each drop must be once it is rounded up to whole pattern repeats, and how many metres that makes. Everything is in centimetres and metres.
The plan works from the figures you type in; the measuring visit checks them against the window itself.
Fabric and cut plan
Change any figure and the plan redraws. The starting figures are the worked example further down this page.
- Flat width of cloth
- 575 cm
- Widths
- 5 — two and a half to each curtain, the half widths at the outer edges
- Drop with allowance
- 260 cm
- Cut drop on the repeat
- 320 cm — 5 repeats of 64 cm
- Face cloth
- 16.00 m
- Lining or interlining, same widths
- 13.00 m
- Cloth taken up by the repeat
- 3.00 m
Fullness starts at about 2 for a pencil pleat or eyelets and 2.5 for pinch pleats. Makers differ — pinch pleats are made at anywhere from about 2 to 3 times the track — and a wave heading’s fullness is set by its track system.
The making allowance is what the heading and hems use up. 30 cm is a starting figure for this plan, not a rule: it depends on the heading and on how the curtain is made, and the maker confirms it before cutting.
For a half-drop match the plan adds one more repeat to the face cloth, as a margin for matching the step between widths; the layout is planned before the first cut.
How the plan counts
- Flat width = (track + overlap and returns) × fullness.
- Widths = flat width ÷ fabric width, always rounded up: 4.2 widths means five.
- Drop with allowance = finished drop + making allowance.
- Cut drop = drop with allowance, rounded up to a whole number of repeats.
- Face cloth = widths × cut drop. Lining and interlining = widths × drop with allowance.
A pair of pinch-pleated curtains for a 230 cm track: 230 × 2.5 is 575 cm of flat width, and 575 ÷ 137 is 4.2, so five widths — two and a half to each curtain, with the half widths at the outer edges. A 230 cm finished drop with 30 cm for the heading and hems is 260 cm; on a 64 cm repeat that is just over four repeats, so five, and every drop is cut at 320 cm. Five drops of 320 cm come to 16 metres of face cloth, where a plain cloth of the same width would need 13 — the repeat accounts for the other 3.
Roman blind folds, and where the cleat goes
A Roman blind is a flat panel drawn up into horizontal folds by cords running through rings on rods. Give the plan the blind’s finished drop, the number of rods and the height of its head above the floor; it spaces the rods and marks where the cleat may go.
- Between rods
- 25.5 cm
- Bottom section
- 12.7 cm
- Rods above the hem
- 12.7 · 38.2 · 63.6 · 89.1 · 114.5 cm
- Each fold, drawn up
- about 12.7 cm deep
- Cleat
- on the wall beside the window, between 150 and 215 cm from the floor
The plan divides the drop the common way: equal sections between the rods, with the bottom section half the height of the others so the hem sits level with the folds when the blind is drawn up. Each fold then hangs about half a section deep. Some makers divide a blind differently; whoever makes yours confirms it.
“New blinds with looped cords must have child safety devices installed at the point of manufacture or be sold with the blind.”
“Tidies and tensioners should be firmly fixed to an adjoining surface to ensure that the cord or chain is permanently held tight. Cleats should be positioned out of children’s reach on an adjacent surface that is at least 1.5 metres from the floor. After blind use, cords should be fastened up in a figure of eight making sure all the spare cord is secured on the cleat.”
The standards for internal blinds and their safety devices are BS EN 13120:2009+A1:2014, BS EN 16433:2014 and BS EN 16434:2014. Every corded or chained blind we fit goes up with its safety device, and its cleat is placed by that guidance.
What the visit adds to the numbers
The plan knows only the figures it is given. At the window the visit adds the things figures leave out: whether a track runs into a corner, how the three faces of a bay meet, how much room the ingo leaves for a blind inside the recess, which way the light comes in, and what the wall will hold.