I've decided to use half square triangles in my border and I think I remember reading you have to measure them bigger than you normally would. Is that right?

This link will give you the measurements you need .karencombs.com/setting_triang.htm

When I make HST, I cut squres 1 inch bigger than I want the finshed size. Sew 1/4" on each side of the diagonal, cut apart and trim to fit.

If you don't want to trim, add a "generous" 7/8" to the desired finished size. Many people feel it's easier and more accurate to add 1" and trim after it's sewn.

This chart is for setting triangles, not HST's.