Prime as in prime numbers:) But don’t worry, there’s no math involved.

Size is totally adjustable to any yarn with corresponding hook.

The pattern includes instructions for normal coasters and also for a larger size to use for a pitcher or bottle.

Yardage obviously depends on how many coasters you make. I managed to get 6 coaster(9,5cm) from one skein. Second skein is needed to make set of eight and the larger coaster for pitchers.