Medallion knitting produces flat knitted fabrics that are circular or polygons using a technique similar to the crochet of doilies, by progressively increasing or decreasing the radius.
The most difficult part of flat medallion knitting is increasing or decreasing at just the right rate.
must exactly equal that circumference times the stitch gauge, if the medallion is to lie flat.
If the number of stitches is fewer than this, the medallion will cup at its edges, forming a spherical bowl; if the number of stitches exceeds this, the medallion will frill at its edges, forming ruffles.
Therefore, one should measure the radius regularly as the medallion is being knitted and determine the number of stitches that need to be increased or decreased in each round.
Most medallion knitting patterns implicitly assume that this will work, e.g., "increase five stitches per round".
However, the knitter's gauges may differ from those of the pattern-maker and may even change with the circumference, and
Here's one plan for knitting a disk: Start with 8 stitches in the first round.
If one begins with eight stitches the pattern above results in eight increases per two rows, or an average of four increases per row which is the "magic number" for flat circular knitting according to Daniel Yuhas in his book "Knitting from the Center Out".