when i do a snowball, i use 6 1/2 inch squares for the center blocks and 2 1/2 squares of black for the corners. for a king size, i would ''guess'' a yard and a half for the corners and 166 6 1/2 inch squares of scraps for the centers. that is making a quilt 12 x 14 rows. then add borders to make it the size you want.
jodi in levenworth
ps......i use a ton of novelity fabrics and then it becomes an eye spy quilt. or do a quilt with all flowers or all dogs and cats...just have fun