No Math Way to Make Perfect Half Square Triangles
Easier And More Accurate
You should add 0.854” for HSTs
The Half Square Triangle Addition Lets You Add the Exact Amount on the Edge of Your Ruler
The Alignment Tabs make it easy to attach the Half Square Triangle Addition right up to the edge of the ruler without any gap, ensuring accuracy.
Slide the Ruler Extensions over the ruler until the Alignment Tabs butt up against the ruler's edge. Then press down on the Suction Cups.
Attach the Add-On to wider rulers like a 12 1/2" square to cut strips up to 15" wide.
Line two Add-Ons up on the 24" Ruler to cut wider strips from the full width of fabric.
If You Need the Suction Cups to Hold Longer, Get Them Wet
If the surface of your ruler is clean & free from scratches
Suction cups work by creating a vacuum when you press them down. They will stay attached until air leaks in.
That's why you want to make sure there are no scratches on your ruler, so it can create a tight seal.
If you put a drop of water on them, the water will keep air from leaking in unitl it completely evaporates, which can take sevaeral several days or even a week or more.
If you already have Grip Strips on your 12" or 24" ruler, you'll also need to put one on each edge of your Quilt Ruler Seam Allowance Additions or Plus 2.5" Add-On, so everything's level.