The pattern suggests size 50 thread and a #14 hook for a vanity set.
Or for a larger set, "use SILAKATEEN-SANSILK... and a No. 12 hook... the small piece will measure about 10 inches and the larger piece will measure about 15 inches square. (Probably a size 40 thread.)
For a luncheon set. use "STAR CROCHET CORD" and a No. 6 hook. (Probably similar to size 10 thread.)
1 day ago