Originally Posted by
dunster
6 7/8 is halfway between the 6 3/4 and 7" lines. However, most of us would cut the squares at 7", make the HSTs, and whittle them down to size.
This is how I do it if only for time saving for me and knowing my HST will always come out like I want them. I use my bias square up ruler from Martingale/The Patchwork Place to square up the HST's.
If you want to do it the 7/8" way then there are a few rulers out there with that marked on the crosshairs of the ruler. You could buy one of them and then store it when not using.