Skip Navigation Website Accessibility
Call Today 804-262-0005
become a fan

Half-Square Triangles


Half-Square Triangles 

Hope everyone has survived the ice and snow, rain, icicles, and fairyland looking trees. Hope you have power, weren’t without it very long, and no trees down near you. We’ve had a few treetops down across the driveway, manageable with a chainsaw. I’ve been home but still busy. Hope you were able to be kept busy too.
                                             
                                                     Yesterday  verses Today
 

This week’s lesson is on half-square triangles. Variations of these are quarter-square triangles, pinwheels, and a square-in-a-square. You can make many, many different looking quilts with just this one shape.

                              

Half-square triangles are two 90-degree triangles put together to make the square. You should have your sides, top, and bottom of your squares lined up on the straight of grain on your fabric. You sew first and then trim off the extra of the seam allowance or cut apart between the sewing. This way you don’t sew on a open bias edge.

Before we start with measuring, cutting, sewing, and trimming - You need to read the pattern directions! See how many half-square triangles and what color combinations it needs. You need to see if the pattern talks about finished or unfinished blocks. Check what the pattern says for measuring the blocks. Finished is the measurement after the block is sewn in. Some pattern directions talk about trimming for unfinished blocks. These are the blocks WITH their ¼” still on them. You should sew your unfinished blocks to the unfinished size needed or a little bigger. If they are bigger, you can easily trim down to the size needed. If they end up too small, you can sew your seam allowance smaller or sew another set of blocks larger. If the pattern talks about finished blocks, you will need to add measurements for cutting and sewing. To get the unfinished size, add ½" to the block measurements. So a finished 2" X 2" block is 2 ½" x 2 ½" unfinished.

 

Making one or two half-square triangles

Figure out what size your starting squares should be:

Finished size ( sewn in block) = X

Unfinished size block = X + ½”

Starting size for sewing = X + 1”

                            

Cut two squares of the colors/prints you want.

Draw a diagonal line on one.
Place squares right sides together.

For one block, sew on the line.

For the one block, trim down one side of the square, a ¼” from the seam.

For one or two blocks, sew on either side of the line. ¼” from the line.

For these one or two blocks cut on the drawn line between the seams.

Press open and trim off dog ears (little pieces sticking out).

Check the size of unfinished block wanted and trim down. Use the 45-degree mark on your ruler to align with the seam to trim.

                               

 

Making 4 blocks

Figure out what size your starting squares should be. Use this chart for figuring out the math (scroll down on the tutorial page to see it).
         

Cut two of the same size, one of each color/print wanted.

Place squares right sides together and sew ¼” all the way around the outsides.

Cut diagonally across both directions.

Press open and trim dog ears.

Check the size of unfinished block wanted and trim down. Use the 45-degree mark on your ruler to align with the seam to trim. 

Making 8 blocks

                                    

Use this chart to figure out the size of your blocks.

Cut two of the same size, one of each color/print wanted.

Mark one of the squares with diagonal lines and lines from the middle of each side to the opposite side.

Sew ¼” from both sides of the line, the diagonal lines only.

Cut on all lines.

Press open and trim dog ears.

Check the size of unfinished block wanted and trim down. Use the 45-degree mark on your ruler to align with the seam to trim.

Here's a cheat sheet for all. You can go HERE to see the whole tutorial.

                                       

We have lots of sizes of square rulers for trimming. We start at a 2 ½” square up to a 15” or 20” square. If we don’t have the size you want, get one a little larger or ask us to order you the size you want.

                                

There is also a set of rulers that trim your half-squares before you press them open. Clearly Perfect Slotted Trimmers. These come in several size ranges and in inch and half-inch rulers.

                                                    

Don’t forget to have rotary blades with sharp edges and no nicks. Re-cutting each cut gets tedious.

 

Hope to see everyone soon. The plan is to be open all week. Please mother nature, cooperate.

Happy and joyful sewing to all,

Phyllis and the QA staff




Quilting Adventures                                                                     Hours: 
6943 Lakeside Avenue                                                                  Tues thru Sat  10 - 4 
Richmond VA  23228                                                                     Sun - Mon  Closed
804-262-0005                                                                                 
Website:  http://www.quiltingadventures.com                          
Shop Blog: http://www.quiltingadventures.com/qablog 
Facebook: http://www.facebook.com/QuiltingAdventuresVA 

 

Click to visit Quilting Adventures!
Contact Info
Quilting Adventures
6943 Lakeside Ave
Henrico, VA 23227
(804) 262-0005
info@quiltingadventures.com

Hours
  • Tues - Sat   10am - 4pm 
  • Curbside pickup  Anytime

  • Sunday - Monday  Closed

Find Us