Tuesday, November 15, 2011

Half Square Triangles Tutorial {3 ways}

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a nice pile of HSTs ready to be trimmed

In preparation for piecing our blocks for our Chasing Chevrons quilt along, I decided to work ahead and show the three different ways that I make half square triangles {HSTs}.  Each way has both pro's and con's and in the end, the method you use relies the most on your cutting, piecing and pressing accuracy.  By rolling this tutorial out ahead of time; hopefully you will have time to practice and decide which method works best for you for when it comes time to piece the HSTs for your Chasing Chevrons quilt.

Please note, the measurements for these methods and blocks are not the same as the quilt along so don't go getting crazy and start cutting your fabric for the actual quilt.  I'm showing the math for figuring HSTs for others who might use this tutorial and well, because I'm nice.  But this is just practice for the real quilt...

Method 1 {my favorite}
Want to make 4 HSTs at once?  Then this is the method for you.  Now, I know there is a bit of controversy over creating blocks with bias edges and this method does that.  However, I would almost rather create a bias edge and use some starch than sew actual triangles together on the bias. 

I have made several quilts, including my Blissful Zig Zags using this method and I have never had an issue with the bias edges.  I certainly would not post a suggested method if I had not tried it myself and had plenty of success. :)

There is some math involved in this method but an easy way to figure what size your HSTs will be it is:

Beginning square size x 0.64 = HST size  

If you know what size your HST should be then use this to find what size the beginning square needs to be:

HSTsize/0.64 = beginning square size


To make 4, 3" HSTs, grab two 5" squares.  Ideally, you want one light square and one darker square to create good contrast.


Place the squares right sides together {RST}.  Stitch a scant 1/4" all away around the perimeter of the block.  Pivot at each corner until you reach the beginning of your stitching. 


What's that you say??  Yes, I know the squares are completely sewn together.  Don't worry... ;)


 Take your squares on your cutting mat.  With a ruler and a rotary cutter, cut diagonally from corner to corner.


Keep the halves together and cut diagonally from corner to corner again.


Open your 4 quarters to reveal 4 HSTs!   Here's where it gets important:  Lightly Press {don't iron} the square open.  Using a back and forth ironing motion will distort those edges!

We will talk more about the often debated directions in pressing seams when we get to that step in the quilt along.  It will be so much fun!

Now grab some starch and lightly mist your open block.  If you have never pieced with starched blocks then be ready to be amazed!  Again, press the block to set the starch.  You can use spray starch in a can if you'd like but I like making my own from this great recipe over at Pins & Bobbins.


Once you are done pressing, you will have 4 finished HSTs ready to be trimmed to size.  If you are accurate in your piecing, you will basically be trimming the dog ears on the corners and that's about it.

Method 2:
This is my second favorite method.  To determine how big your starting squares need to be, add 7/8" the size you want your finished HST to be.


This method will let you make 2 HSTs at once.  Not bad!


Take 2 squares and place them RST. 


With a ruler and a marking pen or pencil, draw a diagonal line from corner to corner.


Pin your squares together and stitch with a scant 1/4" on both sides of the line you drew. 


Once done, take your ruler and rotary cutter and cut along that same line.  Follow the same pressing instructions from above, trim the HSTs and you're done!

Method 3 {my least favorite method}:
This method seems to invite the most opportunities for error.  Of course this is only my opinion; your experience might be different.  It also only produces one HST at a time.  Boooo!

There's still a little math involved in this method.  If you are cutting your triangles out of squares all you need to do is add 7/8" to the desired finished size of your HST.  For example, if you want a 3" finished HST, then you would cut the square to measure 3 7/8". 

Once you have your square, I highly recommend lightly spraying it with starch and pressing the square to set the starch.  This will make your edges a little easier to deal with. 


Next, cut diagonally from one corner to the other to create your two triangles. 


Place them RST and stitch together with a scant 1/4" seam allowance.  Follow the pressing instructions from the other methods.  Trim and you now have one HST complete.

Like I said, this is my least favorite method but I know that some people have an AccuQuilt cutter or triangles that they would like to use up.  If you choose this method... starch and patience are a must because the edges can get funky in a hurry. 

So there you have it!  Make one at a time, two at a time or, four at a time... hmmm.

And lastly, what's a scant 1/4" seam allowance?  Something I didn't bother with until I started making HSTs and couldn't get my sizes to come out right.  Turns out it's pretty important sometimes!  A scant is literally a few threads short of a true 1/4".  Turns out that a few or so threads can add up after opening a block and pressing because of the fold and how our machines stitch with locking threads.


The best way to set your machine to sew a scant 1/4" is a little trial and error.  Take a 5" square and cut it exactly in half.  Each piece is now 2.5" wide. 


If you have a 1/4" presser foot, start there.  Stitch a seam, open, press, and then measure the finished block. 


You have your scant seam allowance correct when your open and pressed piece measures exactly 4.5" wide.  If the measurement is perfect then you've got it! 

If your block is a tad too small, just adjust your needle position to make your seam a little less than a 1/4".  Stitch another seam and measure again.  Lather, rinse & repeat.  It might take a few tries but it's well worth it to have your HSTs turn out correctly!

As always, if you have any questions please let me know.. :)  Linking up for Fabric Tuesday too!

29 comments:

diplofam said...

Jennifer--you are a genius--I have never seen that sew around the whole square method before (could I be the only one?) That looks like a huge time saver--thanks for the tip!!!

Melanie@Crafty Cupboard said...

Thanks for this, I can never remember the math part and end up with strangely sized HST's! You're fabulous.

Chelsea said...

I love the idea of the 4 in one HSTs, I've never seen that one before. I think I'll try this next time I need HSTs. I normally use the 2 in one method but hate that extra step of drawing lines. Ok, not as much as I hate trimming, but I don't think I'll ever be such an accurate piecer that I don't have to trim.

Danielle said...

Thanks Jennifer! Just curious, have you tried the HST ruler? It's a long ruler that has the triangles cut out of it. And it eliminates the need to trim those ears off! I was thinking of getting one. But was wondering whether you'd tried it? Danielle

PS I've recently cottoned on to the scant 1/4 inch thing and it is a revelation!

Kirsty@Bonjour said...

Thanks for explaining the scant measurement. Normally I make my HST a little big on purpose so I can trim them back to perfection, but if I master a scant seam I might save some time.

Grey Cat said...

I personally use a strip piecing method for HSTs, which I detailed in a tutorial of my own: http://greycatquilts.blogspot.com/2011/03/basics-of-pinwheels.html, and I always start a little bigger and trim down, rather than mess with a scant 1/4" seam.

Cindy @ Creating at Home said...

Hello!

Thanks for the great step - by - steps! I had forgotten about the method for making 4 at once. What a great time saver! Have you tried Best Press? I like it as a spray starch. It's not super starchy, which is nice.

I've just designed a Chevron quilt, then a friend sent me a link to your quilt along. It looks like fun!

-Cindy

Happy Turtle said...

I used method 2 the most and also like method one... I made pinwheels that way after watching a tutorial by Jenny Doan form the Missouri Star Quilt company... but I am a little nervous about method 1. I guess I need to get my scant 1/4th inch working. Thanks for the tip on that. :)
Carol

Brandie said...

Pure Genius. I never want to make HSTs one at a time again!!!!

Jackie @ Fred-and-Cissy said...

Thanks for the tips - I also hadn't seen the first method, and it looks more to my liking than the others (I've also done a grid type method before, where you start out with a larger rectangle and end up with about a dozen HSTs, but for the life of me I can't find the instructions!)

Janine said...

I must bookmark this for reference. Thanks for explaining that all so clearly :)

randi said...

i have never seen method one. it looks great AND quick!

Stephanie said...

I have NEVER seen the first method and it is now my favorite method over the second method. I never do method 3, too much cutting. Thanks for enlightening us!!!

Live a Colorful Life said...

Okay, amazingly I have always done method number 3. Haven't tried 1, although I have seen it before I think. I have tried #2 and for some weird reason it doesn't work all that well for me so I'm kinda stuck on #3. But I'm willing to try #1 and give #2 another shot. And yes to figuring out a scant 1/4 inch!

Karen said...

I have not seen the 4 at one time HSTs before..that is right up my alley!

Gmama Jane said...

Well shiver me timbers...#1 is a new method to me and one I likey likey!! Will be giving it a try tomorrow.
Blessings
Gmama Jane

Elsa said...

great tutorial ~ want to try the first one ~ you get four out of one!

Anonymous said...

That first method is a recipe for disaster, piecing the HSTs so that the bias edges are on the two outer sides. Highly not recommended :-)

emedoodle said...

I love all these methods right here together. I've tried them all and prefer to use method 2. Although I just saw a ruler in a book somewhere that I should have - with a notch down the middle for marking those center lines! A couple thoughts - I like to make half-half square triangles from my flying geese units. I just draw the line for the geese part, then draw a line 1/2" away from it on the scrap side. Extra units from what I'd usually throw away. :)

Also please do share about the pressing... I have resorted to pressing the seams open with my swoon blocks because they end up a huge mess on one side when you sew them together certain ways! No fun!

Sarah said...

I think I use Grey Cat's method when I can have lots of the same pairs. Generally I get squares that finish the same size as the strip. But I love knowing the math to get the beginning squares for the first method! :)

Connie said...

Wonderful tutorial, thanks for sharing!

a.niza said...

Awesome tute. I am Number 2. Until I found and tried 8HST from 1 square. I followed this tutorial

http://www.quiltingboard.com/tutorials-f10/fast-way-do-8-time-half-square-triangles-hst-straight-grain-edges-t141047.html

SarahZ said...

I thought method 2 was a revelation when I first found it...now a new revelation! Thank you for method 1! The more HSTs, the merrier!!!!

thisyearsdozen said...

I haven't tried the first one yet but I did see Jenny at Missouri Star demonstrate it via video. Really cool!!

Suzanne said...

I could NOT be happier to have seen this tutorial. I have made HSTs using method 2 and maybe 3 but ONE? No?! I'm super excited to try this one out. Thank you for all the details.

Sherryl said...

Jennifer - I just discovered your blog and I love it. I especially love this little tutorial about half square triangles... BUT how does .64 correlate to my cutting measurements? Is it equal to a 1/8th or 1/16th of an inch in some way? Can you provide further assistance to the mathematically impaired? Help. I'd really love to take advantage of this process! :-)
- sunshdws at yahoo.com

Pam said...

Love that HST idea. Thank you so much!

a ji o ji suno ji said...

Glad to know that people like the sound of this simple dish that I just loved. Charlotte, maybe I will switch to edamame now and you can switch to chickpeas! (Oh sigh, if only I could find shelled
German Shepherd Puppies

Carmen Lee said...

Jennifer, I just love your blog! Especially this tutorial is very nice about half square triangles, such an easy steps. Thanks for sharing.

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