Half square triangle sizing help!!!
 

Well, math has never been a strong point and today I am baffled. I am making a simple block 12 1/2" and am going to do half square triangles, but cannot figure out the size of the squares, everything I am reading or watching on u tube has muddles my after christmas burnt out brain. Can anyone tell me how big the squares have to be? Please. I am attaching a pic from EQ7 of the finished 12 1/2 block. Thanks so much.

The squares should be 7/8" larger than your finished square. 12 1/2 + 7/8 =13 3/8.


for quarter sq. triangles the amount to add would be 1 3/8. 12 1/2 + 1 3/8 =13 7/8.

Bakermom has it. Those are quarter square triangles in your pattern. Though did you mean a 12 1/2 finished or unfinished square?

though I always make mine a tad bit larger so I can trim them just right.

ali

First of all, if that's a full block ... those are QST not HSTs

Each 1/4 section of the 12-1/2" block (unfinished size) would be 6-1/2"x6-1/2". So each QST would be this measurement before sewing into the quilt block.

If the 12-1/2" you have given is for the finished block (after it's sewn into the quilt) you would need each QST to be 6.75"square.

Same measurements if you are using HSTs instead of the QSTs

The block will be 12" finished. They are qst, but the design is hst. Eggnog brain today. I just cut 6.5 squares, and marked them and now will sew them. I thought my 6 1/2" was correct, but for some reason the 7/8" rule didn't work in my brain.

If you are sewing 6-1/2" squares together to make HSTs, you will NOT have 6-1/2" finished. You need to add the 7/8" to the finished size .... so you want 6" finished, then it'd be 6-7/8 cut sizes for the HSTs .... I always add the full inch to give some wiggle room, and lets me square up nicely.

Likewise the added amounts if you're doing the QSTs

Okay, I'm really confused now. You say they're QST but the design is HST? I can see that the center, if you made that first, could be made as 4 HST's put together, but then you would have to add the corner pieces. It would be much easier (IMHO) to make each corner unit as QST's and then put the 4 of them together.

EQ should give you all the cutting information, but I'm not sure how it looks at this particular block.

Hello. Here's my answer. The design you gave us is what I have always called an "hourglass". In order to keep the bias from stretching so much, it is suggested that you cut your squares 4 ways--quarter square triangles (QST). To make QSTs, your squares must be 1 1/4" larger than your finished squares. So, if your 12 1/2" block is one hourglass, then you must cut your squares 13 1/4" and cut them 4 ways. If, as your pictures suggests, you are using 4 hourglass blocks to make each 12 1/2" block, then you cut your squares 7 1/4", cut them 4 ways, and after sewing a bunch of hourglass blocks (which would make 6 1/2" blocks unfinished), sew 4 together to make your intended block. When I want really scrappy ones, I use graph paper to make my large block (like 13 1/4"), mark it for the QST, cut them apart, then I simply place one on my scraps and cut. I do try to be careful to put the long edge on the grain so that it is not so stretchy. The blocks fit together so much better using QSTs. Ask me how I know??? LOL!

Joyce

Wow, I understand this, thanks Joyce. This makes sense to me!!!

You can print out the block pieces in EQ and then measure as a guide to cutting size.