Just a good assortment..no "uglies" stuck in the middle. Batiks or cottons. At least 40--50 would be better. 20 is just not enough. Definitely no doubles and last, but not least, 2 1/2 inches. Not 2 3/8 or 2 5/8 or 5 different sizes! There has to be a way to cut perfect 2 1/2 in. strips!