Cutting help requested
 

Hello Everyone, I am doing a lot of cutting this weekend and need a little help. I don't know what the quilting term is for when you take 2 squares and draw a line corner to corner and then measure out 1/4" on each side and sew on those lines and then cut them apart and you have a 2 colored block all done. But my question is: All my solid color blocks are 2.5" the half inch is seam allowance. Now, how big do I cut those blocks that I need to make 2 colored so when I open them and press them, they are also 2.5"???? I was thinking 3"? I thought I read once to make them 2 7/8" but how would that make a 2.5" square if you are taking out 1/4" on each side of the middle line you draw? This is so confusing to me. Can anyone explain this to a newbie who is confused? Thank you so very much Rachel

Those are called half-square triangles.

The 7/8" measurement is needed because an angled seam ends up taking up a bit more than a quarter inch allowance when you measure it from one of the horizontal or vertical seams. Just like the angled line you draw from corner to corner is longer than one of the sides would be. So there's jut a tiny bit more added in to make up for that extra.

But I am awful at making these turn out right, so personally I'd go for the 3" squares and then trim them back down after they're made. :)

I would definitely use 3" squares and trim them after they are made. Welcome to the world of quilting! This is a great place to come with any questions--there are many knowledgeable and nice people here to help you.

Welcome to quilting, Shayarene. The puzzle about half-square triangles is exactly as sewnoma said. But you know how geometry and trigonometry can give you some crazy answers with lots of numbers to the right of the decimal point? The actual measurement isn't exactly 2 7/8"... it's just the closest measure that all of us can cut from a ruler measurement. So, I'd vote for making those 3" squares and trimming them. I know, it sounds like a lot of work but, oh my.... what a difference it makes. Trimming has been the life saver on so many quilts I've made.

I also concur with the three inches. There will be waste, but it is worth it to me to know I have enough fabric to make whatever it is I'm sewing.

I also vote for 3" then trimming. I credit Deb Tucker for changing my mind about this. Accuracy of matching points and seams is extremely important to me. Her rulers for trimming down accurately have changed my piecing methods. IMHO a little waste is worth it for accuracy.

I am someone who does not like extra work, at all, but I found rounding up an inch and then trimming when making half-square triangles to be totally worthwhile.

I would go with the 3" squares and cut them down. I always like to square up my blocks anyway.

Do not try to figure out the math. This is really magic or a mystery like the bermuda Triangle! . Cut all blocks 3" and mark on the wrong side on the diaganal. Then sew 1/4" on either side of that line and the cut up the middle Your blocks should be slightly bigger that 2 1/2" so trim then to be 2 1/2"

Trimming is the one thing I hate among all quilting tasks, so I use the 2 7/8". However, I will look up these Deb Tucker rulers. If I had a way of trimming accurately, I wouldn't hate trimming so much!

Here's a little explainer about HSTs and QSTs for beginners:
http://www.colormequilted.com/2014/0...he-difference/

Also, go get an Angler II to tape to your machine & you wont have to mark all those lines. Just hold the point on the line through the machine. I highly recommend it.

https://m.youtube.com/watch?v=UcmUnv3d4mM

I watched the video on the Angler II. I think I'm going to have to get one of those. II'm doing an hourglass quilt with over 300 3.5" blocks. Lots of diagonals.

i alwys make my HST a little bigger and trim them down. I bought the Bloc Loc ruler for HSTs last Saturday at the Grand Rapids quilt show. She only had the 6.5 inch one left but worked for the 2.5 blocks I was making. Very pricey though!

I LOVE my Angler II. It really really helps, especially for smaller HST's. If you are not 'experienced' cut the squares at 3 inches and trim down. Note how you are pressing them and how that MAY distort the triangle. Get into the habit of finger pressing the seam and then setting the iron on the block to press. Try very hard not to move the iron around.By the time you've done a hundred or so, you might want to try cutting the squares 2 7/8 to begin with.

I like accurate half square triangles but LOATHE trimming too. I use a ruler that let's you cut your triangles accurately. You only have dog ears on one corner. You add 1/2 inch to your desired finished size. You cut strips of each fabric for the triangles and layer them right sides together. You place your special ruler with a marked flat triangle against the top edge of the fabric and then line up the marking on the bottom of the fabric . Cut , then rotate the ruler to cut the next triangle, lining up the edge that you just cut. It takes a little practice,I started by cutting too generous and had to trim. LOL After practicing a bit, I can make pretty perfect blocks this way. It is way easier on my hand and wrist. The ruler is purchased at joann by Sharon Hultgren called Easy Angle. There is another one that also makes half square triangles as well as quarter squares for flying geese center. It is the Half and Quarter Ruler by Fons and Porter.
I believe that Bonnie Hunter uses and demos the EasyAngle on her website called Quiltville.com. It is amazing that there is absolutely no waste! You do need to be very accurate in your sewing and cutting.

I just made a bunch of those blocks and it had me cut a 4 7/8 block for a 4.5 unfinished block. Doesn't seem logical does it? If you use the Deb Tucker Tucker Trimmer ruler, she says to cut .5 larger than you need and then trim it to size after stitching together. As I tend to not stitch a straight line I think I'll use Deb's method the next time and to heck with wasting a little extra fabric.

I just finished a mystery quilt that called for over 400 half square triangles. I used a method whereby I doubled the size of the unfinished square (3.5x2) added 1 inch (7+1=8) cut 2 8" squares laid right sides together, used the Fons & Porter quarter ruler to mark corner to corner, sewed along each, cut on center, & and cut across at half way & up an down at half way. Opened them up, trimmed to 3.5" & had EIGHT perfect half square triangles & all 16 stars have perfect points. There is a tutorial on this somewhere, try YouTube, this method s GREAT for large quantities f half square triangles.

Another way to mark your sewing line is to simply fold the square on the diagonal and press.

And the Companion Angle Ruler.........these 3 are really GREAT!!

At a class I am taking, the instructor turned us on to the TRI REC rulers....could not believe it!! There is a line marked on the ruler for the finished size of your triangles ( half square triangles ) and you line up the ruler on a strip of fabric and cut - the end result is blunted corner for matching and perfect half square triangles with NO NEED to be trimmed......I am a lousy cutter, and mine have come out perfectly ( have made over 100 for this quilt I am working on )......

Welcome to the board from Ca. You will find lots of help and fun here

It will be only slivers of waste. Definitely worth cutting the initial squares at 3" rather than 2 7/8".

I've been quilting for a lot of years, however, the only way I can consistently wind up with a 2.5" square is to cut the 2 squares 3", draw the diagonal line, stitch 1/4" on either side, press, then I trim down to size. It requires an extra step, however, my blocks need very little squaring up and I think I make better quilts this way.

I thought you added 7/8 to that you want the finished size to be but I could be wrong

Shayarene, welcome to quilting, but be warned, it is addictive and you could suffer from quilt pox, no cure known. LOL. Just kidding. On the half square triangle there are lots of ways to do a short cut. If you go to Missouri Star Quilt Co, Ginny has some neat ways to do half square triangles. You could also do a google search and probably find a video on making them on u tube.. Best of luck to you.

solstice3 I am pretty sure you are right

Thank you so much everyone, I am going with the 3" As a beginner, I would rather trim than mess them all up. LOL
I had a great day today, I cut strips with my new rotary cutter and mat It went really slow for me because I was so nervous, I just pray I have them all straight. LOL I cut out 600 little 2.5" squares and tomorrow I have another 600 to cut out and then another 600 of the 3" size, then I am excited to say, I am ready to start sewing them all together. I can't wait to see my first block I love this board, everyone is so helpful and knowledgeable. Thank you all so much Rachel

I am with the majority and would go for the 3" and trim your HST, if they aren't right then your whole project will be off. I just finished an inverted star and if I hadn't gone with the extra I would have never gotten all those little HSTs to fit together so nicely. This board has so many members with so much knowledge about quilting you will be hard pressed to find a finer source of information.

Just use Thangles or the other papers for piecing the 1/2 square triangles.They are available at most quilt stores.Easy peezy.