These half-square triangles needed to measure 2 1/8" x 2 1/8", so I used my
favorite ruler for trimming when I need eighth-inch accuracy: the Creative Grids Ruler Itty Bitty Eights 6x 6 Square. Since this ruler is one I keep right at my cutting table for frequent use, I thought I should share a few things about it.
A lot of rulers don't include 1/8" markings, so they can't accurately be used when trimming blocks to the nearest 1/8" increments (1/8", 3/8", 5/8", and 7/8"). Since the 1/8" markings on this ruler are easy to see and because they extend vertically and horizontally on the entire surface of the ruler, it's easy to use the Itty Bitty Eights ruler for trimming half-square triangles in any measurement up to 6" x 6".
I made my half square triangles over-sized and then ironed the seam open from the wrong side, pressing again on the right side of the block. I then placed the ruler on top of the block, lining up the diagonal line with my seam line. Since my half square triangle needed to measure 2 1/8" x 2 1/8", I made sure the 2 1/8" lines were inside my unit. Then I trimmed the right and top edges of the half-square triangle block even with the ruler.
I then flipped my hst so the trimmed edges lined up exactly with the vertical and horizontal 2 1/8" lines, still keeping the diagonal line on the ruler lined up on my seam.
I again trimmed the right and top edges of the half square triangle block even with the ruler. The result is a perfect 2 1/8" x 2 1/8" half square triangle with the diagonal seam exactly in the middle of the block.
Trimming takes a little more time, but to me the accuracy is worth the extra effort, especially when making blocks that need 1/8" precision!
What would we do without the amazing tools available to us today?! I know my great-great grandmothers could probably never have dreamed of all the gadgets we have available for our quilting!
Thanks so much for stopping by!