Threadsmith Marker Layout

What it is for

Before you buy fabric you want to know how much you need. The pattern envelope gives one figure for many sizes and widths; your own pattern (or your size) needs its own answer. In production the same question is called a marker: the plan of where every piece sits on the fabric.

This tool lays the pieces out on the width you have. Every piece keeps its grainline along the selvage; it may be turned 180° unless the fabric is napped or has a one-way print, and 90° only when you allow cross-grain cutting. Pairs get a mirrored copy, pieces cut on the fold are unfolded on open fabric or put against the fold of folded fabric. You get the marker length — the fabric to buy — and the efficiency, the share of the fabric that ends up in pieces.

Pieces come either from a JSON list (polygons or SVG paths in cm or inches, or the whole result of the Pattern Block Drafter) or are drafted on the spot from bust, waist and hip. The layout is a fast deterministic heuristic, not a mathematically optimal nesting, and it does not match stripes or checks.

Worked example

The first example is a known answer: four 50 × 25 cm rectangles on 100 cm wide fabric. They fill the fabric completely, and the tool finds it — marker length 50 cm, efficiency 100 %, lower bound 50 cm.

For a real garment we drafted skirt, bodice and sleeve blocks for bust 104, waist 88, hip 112 cm and laid them on 150 cm fabric:

• open, single layer: 162.8 cm, efficiency 69.61 %, 7 pieces (the skirt back and the sleeve twice, one mirrored);
• folded lengthwise: 163.1 cm on a 75 cm usable width, 69.5 %, 5 placements because each cut goes through two layers;
• open with cross-grain allowed: 151.1 cm, 75.02 %.

So for this outfit about 1.65 m of 150 cm fabric is enough, and a fabric without a direction would save another 12 cm.

How to read the result

• Marker length is what you buy (add a little for shrinkage and straightening the grain).
• Efficiency = area of all pieces ÷ (length × usable width). Garment pieces with curves typically land between 65 and 85 %.
• Lower bound = piece area ÷ width. No layout can be shorter; the gap to the real length shows how much the shapes waste.
• Placements give the corner position and the turn of every piece, with (R) marking mirrored copies in the picture.
• The exact check confirms that no two cutting lines overlap and every piece lies within the width.

Tips and common mistakes

• Enter the usable width: selvage to selvage minus the edges you will not cut into.
• Use folded fabric when your pattern has pieces on the fold — it saves cutting each pair separately.
• Tick Napped or one-way fabric for velvet, corduroy, satin with sheen or directional prints; the layout gets longer but every piece points the same way.
• A finer raster (2 mm) packs a little tighter but takes longer; 5 mm is a good default.
• A gap of a few millimetres makes the cutting easier with scissors.

FAQ

Can I paste the result of the Pattern Block Drafter?

Yes. Paste the whole result object; its cutting lines are in millimetres and the fold lines and pairs are taken over.

Why are some pieces shown once although I cut two?

On folded fabric one placement cuts both layers. On open fabric you see every copy.

Why is my piece rejected as too wide?

With the grain along the selvage, its width across the grain must fit the usable width. Allow cross-grain placement or use wider fabric.

Is the layout optimal?

No — it is a deterministic bottom-left fill that tries three piece orders and keeps the shortest result.