This is my way...
Must choose size of finished block, so we can figure out the "Unfinished" size we need to make our Half Square Triangle [HST] .
**** Finished block is a block sewn into a quilt, so seam allowances are gone. It is what the "Finished" block or square will look like. Unfinished block is the block with the seam allowances. You will need to know this to make more than one and to be able to plan out your quilt, figure yardage needed etc. ****
So say you choose 2 1/2" finished square, so that would be a 3" unfinished square..
****Why? Because 2 1/2" square needs a 1/4" seam allowance on both sides of it so it can be sewn into your quilt..so 1/4" Seam Allowance + 2 1/2" square + 1/4" Seam Allowance = 3" unfinished square... once sewn it becomes a 2 1/2" finished square. ****
BUT... we need some fabric to accommodate making the HST!!! So we are going to add 1/2" to the unfinished square size which make it 3 1/2" square to make the HST.
****Why? Because 2 1/2" square needs a 1/4" seam allowance on both sides of it so it can be sewn into your quilt then it needs a 1/2" to accommodate the HST diagonal cutting ..so 1/4" Seam Allowance + 2 1/2" square + 1/4" Seam Allowance + 1/2" HST extra = 3 1/2" unfinished square... once sewn it becomes a 2 1/2" finished square. ****
Need two different pieces of fabric.
****Can be two different colors Can be two different patterns But they need to be different or you won't be able to "See" the half square triangles.**** [In the image below I chose 2 different fabrics, and cut two of each fabric. You can do just one, but if you haven't used my way of making a HST then you will need this extra set to make a master. Once you have tried my way and like it then you don't have to make the master any more. And if you try it and don't like it you can always throw it away or in your stash box!]
Cut two pieces of fabric. Each to be 3 1/2" unfinished square size.
Now stack the two fabrics, Right sides together.
**** Right sides together means the "good" side or "best" side or "What looks right side" in short we say "Right sides together", Wrong side would kinda defeat the purpose ****
Now "Old" school says we are to draw a line from one corner to the diagonal corner. Then using a 1/4" foot or your "eyeing" a 1/4" space, you are to use the dawn line to guide you as you sew down each side of the diagonal line. Your sewn line is to be a 1/4" away from diagonal line on each side of the diagonal line.
Well remember I cut two pieces of fabric of each kind so you actually have two sets? We are going to use one of them to make a "master" so we can tape our sewing machine so we don't have to draw lines on every HST. Cut on the two outside lines which leaves you with a left triangle, a center with the penciled diagonal line on it and the right triangle. Toss the two triangles in your stash or trash. Keep the center part.
We are going to use the "center diagonal line" piece of fabric. Insert your needle right on line at one tip. Then using Blue painter's tape [I used 1" wide size], tape down each side of the "center diagonal line" piece. Like you see in the following picture. Once you have the tape down, raise the needle, and remove the "center diagonal line" piece. [can keep for another time or throw away].
Now using the "Other" stacked two pieces of fabric, with no lines on it, place the diagonal points on the blue tape on the right. You are going to sew with you holding the bottom point aligned with the blue painters tape on the right [>>>> that way]
Once you have sewn down the one side. DO NOT take it out or turn it around. Just slide the double piece over to the left [<<<<that way] so that the diagonal points are now aligned to the blue painters tape on the left side. Sew while holding the point aligned with the blue painters tape.
Take your "Square up Ruler", or ruler with a 45 degree diagonal line on it and with one edge marked for the 1/4" seam allowance. Using this ruler, lined up from diagonal tip to diagonal tip, cut from tip to tip. [See image]
Once you have it cut into two parts, you will need to open them, and press them open.
Once pressed opened you will need to trim your HST.
Using the "Square up Ruler" or ruler with 45 degree angle mark on it.
Place the diagonal mark on ruler over the diagonal line made by sewing the two pieces together.
Move your ruler until the 3" mark is showing on all sides, top and bottom of square, also keeping the diagonal line on both ruler and fabric square lined up.
You should see the edges of your square lined up pretty close to the 3" marks
..... WAIT... where did that 1/2" go that we added for the HST? it got lost in the diagonal seam, Don't ask me to explain I didn't take algebra or geometry!!
1. There are two thick marks that outline the right side of the 1 inch lines, the 2 inch lines and the 3 inch lines.
2. The fabric needs to be even with those lines and the far Left edge of the ruler and the Bottom edge of the ruler [in other words those should be the 3" out line of your square, all else is extra that we will trim.
3. IF there is any extra past the ruler on the left or bottom use cutter and trim that extra off.
Now leaving the fabric square where it is, turn your Ruler around so the 3" lines are now aligned with the trimmed left side, and the untrimmed side is on the top and right of the ruler.
Making sure that the diagonal line on ruler is on top of the diagonal line on the fabric, move the ruler until the clean edge of the left and bottom side are even with the 3" lines. If there is any extra past the top and right side of the ruler then trim that extra off.
Remove your ruler and it should look like the above a perfect 3" HST unfinished... once sewn into quilt the 1/4" on each side will be used and it will finish out at 2 1/2".
Some will say a couple of things...
WHY this way instead of marking with pencil and sewing up one side then turning and sewing down the other side... Because I am tired of stopping, getting pencil and ruler and marking the HST diagonal line, when I can have from 98 to 1500 HST in a quilt. With this method you can actually chain sew down one side a whole slew of them. When you get to the last one remove chain and clip them apart, then line up and go again on the other side. Then cut, press, trim as usual.. it saves time!
WHY did you only use a 1/2" extra for the HST diagonal seam, instead of the usual 7/8" others use. It is my choice, less to trim if your following your guides you don't need all that extra. IF you have a hard time staying aligned up and need the extra then go ahead and use the 7/8" or more and then you will have more to play with when trimming... it is a choice... this is mine.
BUT BUT BUT, Remember the line "There are no Quilt Police", that applies here It is choices!! I choose to do mine this way and save the marking time... Also I didn't get straight lines doing it with aligning with my 1/4" foot, seems my 1/4" foot moves because my lines were never straight... with following the blue painters tape with the tip I don't have to watch the 1/4" foot.. saves my brain power.
Hope this helps!! Please let me know if you find a error or if you have questions!.
Happy Quilting, sewing or browsing...lol
Becky
