Bloc Loc Ruler - My Fav

When I first began quilting I joined a quilt guild in the community where we were living. The guild was perfect for me as they brought in many "experts" and I learned so much from them. One such "expert" was Janna Thomas. She created this tool out of frustration in trimming, or squaring up, what we quilters call half-square triangles (HST for short - read on for an explanation).

The Bloc Loc ruler is my absolute "must have" and my all-time favorite ruler. It's a square ruler, coming in many sizes, and has a channel along the diagonal. 

For the uninitiated, a HST is made by sewing two right triangles together along the diagonal (or in geometry terms, along the hypotenuse - the Math teacher in me just had to include that bit!) Most often sewing along the diagonal causes the fabric to stretch a bit,  or become slightly distorted, and the resulting piece is no longer square. In order for the HSTs to be sewn together accurately, or sewn to other squares, they must be trimmed to make a square. 

Trimming HSTs simply requires a ruler with gridlines of just about any size or sort. The ruler may be laid on top of the HST and positioned in a way to assist in trimming the pieced block to form a square of the required size, with the diagonal seam remaining the diagonal of the square. If the ruler you are using isn't the size of the block you need to cut, you can either be careful in lining up the lines of the ruler, or use tape to mark the size you want. It's pretty simple, right? 

Well...maybe not! Because of the thickness created by the seam allowances generally ironed to one side along the diagonal a flat ruler rocks and is easily twisted from the diagonal as you try to use a rotary cutter to trim the edges. This makes cutting a true square a challenge. Janna was frustrated by this. She tried putting layers of tape along the diagonal to make up the difference in thickness. She realized if a channel was cut into the ruler along the diameter that would  accommodate the thickness of the seam allowance, the ruler would "nest" along the diameter and while cutting the HST would not be as inclined to twist. Brilliant! And thus, the Bloc Loc was born. 

Sadly, Janna passed away in February, 2025. However, her legacy lives on and the Bloc Loc is available for purchase from numerous vendors or directly from the BlocLoc website at https://blocloc.com/