Read a filet crochet graph from the bottom up; the first row of stitching is at the bottom of the graph. Each block in the graph or chart depicts a block of four stitches. A block that is filled in or has a dot inside represents double crochet stitches. An open block represents a sequence of one double crochet stitch, two chain stitches and another double crochet stitch.
Patterns may refer to filled blocks as closed mesh or solid blocks (or as just blocks), and to open blocks as open mesh, blank or empty blocks.
Work odd-numbered rows from right to left and even-numbered rows from left to right. The number of stitches in a row is three times the number of chart boxes plus one, so a row of five chart boxes has 16 stitches. The first and last blocks in each row are usually closed blocks.
Although each block contains four stitches, two adjacent filled blocks or a filled block next to an open block share a double crochet stitch, so the two blocks together have only seven stitches rather than eight. A row of nine filled blocks has only 28 stitches, not 36. Visually, this results in one thickness of thread forming a vertical column with a hole or space on either side of it.