Filet Crochet Chart Maker

How to make a filet crochet chart

1. Start from a name, a silhouette or a drawing. Name mode gives clean block letters; Draw gives a blank grid where Pen fills squares and Eraser opens them.
2. Set the width in squares. Each square is 3 stitches plus one closing dc per row, so width drives the foundation chain directly.
3. Check light and dark. The maker splits light from dark automatically. Press Invert if you want the motif open on a filled background instead.
4. Chain the foundation. Read "Foundation chain" (3 × squares + 3) and the note on how Row 1 starts, open or filled.
5. Work Row 1 right to left. Follow the written rows: open = dc, ch 2, skip 2; filled = 3 dc. Then alternate direction every row.
6. Track and print. Move the row marker as you go and print the chart on one page for free; the paid row worksheet has every row with a tick box, and the large-print chart tiles the mesh over sheets of 9 mm or 6 mm squares.

How filet mesh works

Filet crochet is a grid of double crochet posts. Every square on the chart is 3 stitches wide: the dc that closes the square plus either 2 chains (an open square, or space) or 2 more dc (a filled square, or block). A row of N squares is therefore 3N + 1 stitches, the extra one being the dc that closes the last square. Rows are 1 dc tall. On the chart a filled square is solid and an open square is empty, so the picture appears as solid thread on a mesh, or mesh on solid when you invert it.

Here is the name ROSE at 30 squares, drawn by the maker's engine; dark squares are filled, light squares open:

The foundation chain formula

Foundation chain = 3 × squares across + 3. The first 3 chains past the work become the turning chain, which counts as the first dc of Row 1. If Row 1 begins with a filled square you dc in the 4th chain from the hook and in the next 2 chains; if it begins with an open square you chain 2 more and dc in the 8th chain from the hook. That rule follows the standard instructions in Crochet For Dummies (Wiley): "multiply the number of blocks in the row by 3" and "add 3 more chain stitches for the turning chain".

Thread, hook and square size

Filet is traditionally worked in mercerized cotton thread with a steel hook, which gives small squares and fine pictures; the same chart in yarn turns a table runner into a blanket panel. These are approximate square counts for firm tension; your swatch is what counts, and you can enter it in the gauge fields.

Thread sizes are US crochet-thread numbers; a bigger number is a finer thread. Approximate; work a swatch.

What makes a good filet picture

Filet has exactly two tones, so it rewards strong silhouettes: a black cat on white, a heart, block letters, a flower outline. The maker converts a picture by measuring the lightness of each square and splitting light from dark with Otsu's threshold, which picks the split that best separates the two groups; you can flip the result with Invert. Pictures with soft gradients, faces and low contrast tend to turn into noise. Keep motifs at least 3 squares thick and leave a border of 2 or 3 open squares around them so the edge of the piece stays straight. Because filet is worked in one thread, switching between open and filled squares is not a color change; the crochetability check only counts lone filled squares (a filled square with no filled neighbor, diagonals included), which tend to look like noise, and can preview opening them up.

Looking for a filet crochet pattern generator for a name? Name mode is built for it: letters are 7 squares tall before scaling, so a four-letter name fits in 30 squares, and the foundation chain and every row are written out for you, in US or UK terms (UK patterns say tr and miss where US patterns say dc and skip).