Monday, August 9, 2010

Half-square triangles tutorial


I've had several questions about how I did the triangles for the quilt I'm currently working on, and I thought maybe I'd give you all a little how-to. This is the way my sister taught me, and it has several advantages, the main ones being that it's fast and hard to screw up. Those are generally my criteria with any quilting method: fast and hard to screw up.

There is one main tool that you will need for this method, though it could conceivably be done without it. I use this ruler, from Quilt in a Day by Eleanor Burns:

From The Bitchy Stitcher

Inside the package, she has a chart for cutting your fabric. So, you choose the size you want your finished HST blocks to be - I chose 3 inches (or 3 1/2 unfinished) - and then cut out your fabric in large squares according to the chart. To get HSTs at 3 inches, my big squares need to be 8 inches.



I cut 90 8-inch squares from several batik fat quarters and 90 8-inch squares from Kona cotton in white.

Before placing two of the squares together, take one square (in my case I always used the white, so the marks would show easily), and using your preferred fabric marking tool and a ruler, draw an x across the square from corner to corner (on the wrong side, if using a print):


After marking, lay your two squares together (right side to right side if not using solids or batiks). Pin at each side to hold in place. Using your marks as a guide, stitch along both sides of each line, using a 1/4-inch seam allowance.




Remove pins and press to set stitches.

Now, you are going to cut this square 4 times. Once along each of your drawn lines and once vertically and horizontally. This will produce 8 triangle-square units




Each block you have just produced will be slightly larger than 3.5 inches, so you'll need to trim them. Before pressing them open, lay your Eleanor Burns-approved ruler on the triangle, with the appropriate line on the ruler over the seam line on your block, like so:




Trim the excess on either side of the ruler.


Press open and trim the little tails from the corners. To make 8 blocks from one 8-inch square probably took me between 5 and 10 minutes, with the longer times having more to do with the constant interruptions from my children than from any difficulties. So assuming even 15 minutes for each set of 8, it took me about 3 hours total to make 720. Not that I did it all at once. Even I have a limit for how many times I can repeat the same task over and over in one day.

I'm sure someone with a head for such things could figure out how to do this without one of Eleanor's fancy-schmancy rulers; any right angled ruler would do if you can figure out how to mark that seam line. I noted that the red line for a 3.5-inch square is exactly 2.5 inches from the corner of the ruler. (Okay, here's how. Take the size of your unfinished square - in this case 3.5 - and multiply it by the square root of 2. Then divide that number in half. There's probably a shorter way, but I have to think of it that way or I get confused.)

I hope this helps make half square triangles (or half triangle squares, whichever seems more accurate to you) not so scary and daunting. Next I'll show you how I figured out the layout for the quilt. 

Now please enjoy this cartoon from the inimitable Natalie Dee:



www.nataliedee.com
www.nataliedee.com

10 comments:

Anonymous said...

I like your writing style. I can easily follow along in my mind, except for what is either an error or else I haven't had enough coffee.

"After marking, lay your two squares together (wrong side to wrong side if not using solids or batiks)."

Wrong sides together?

Bert in Rice, WA [off to get more coffee]

Anonymous said...

I like your writing style. I can easily follow along in my mind, except for what is either an error or else I haven't had enough coffee.

"After marking, lay your two squares together (wrong side to wrong side if not using solids or batiks)."

Wrong sides together?

Bert in Rice, WA [off to get more coffee]

Megan said...

You're right! I fixed it -thanks!

Sarah Craig said...

OK, I stand amazed!! What a simple way to make 8 identical HSTs at once! Thanks for sharing!!

Wendy said...

Thanks Megan! I love QIAD rulers but love the math tip you give on the end ... I'mma gonna print that off now and post it to my literal forehead when I make these silly things because otherwise my brain cannot wrap around how big to make the squares to get certain size HST. You rock (as usual)!

helen-mary said...

I love Eleanor Burns. That woman is worth every penny she's ever earned. That also happens to be one of my favorite rulers. You are doing your readers a GREAT service with that post.

Littlebook said...

Honestly, this post rocks! You are a goddess for posting this. I'm going to run out and get one of those rulers and throw myself into HST heaven (or hell if I do as many as you did).

Patty said...

OK so after I multiply by the square root of 2, is it then that I divide it by pi????????

Megan O said...

I HAVE DONE IT. I have read all of your blog posts :) success.

Katie said...

I have heard of this method of 8 HSTs at once - but never the trimming before pressing method... this is even more easy no fuss no muss. Thanks! and btw I was searching for the 8-at-once HST method for Bonnie's mystery quilt that's going on right now - which just so happens to be 3.5" finished 3" finished! <3 <3 <3 ya for that !
(Katie has a really hard time not stretching tiny triangles)