7x7 inch blocks what is the reason
 

i have a pattern that calls for 7x7 inch blocks for half square triangle then to cut them down to 61/2 square. what is the reason for doing that instead of cutting them to 61/2 squares to begin with. I would appreciate any help you can give me. I am waiting to hear from you before i start this quilt

When you sew them together corner to corner you will loose almost all of the 1/2 inch, when you cut them down after sewing the 2 parts together you only cut off a sliver. Also sometimes when you sew them corner to corner the fabric twists and cutting down after you get your stitching done makes sure the square is really square...

Does that help?

To make it more accurate due to the bias when you make it exact it stretches and can distort easily versus cut down to the perfect size

Because if you cut them 6.5 they'll turn out too small. To make half square triangles you add 7/8ths to the *finished* size which is the measurement after it's sewn into a quilt. So if you're making half square triangles to go with 6.5 inch squares they have to start at 6 7/8ths. Since 7/8ths is hard to cut and half square triangles don't always come out perfect you just add that extra eighth and square them up after you make them. When you square them up you'll trim them to a perfect 6.5 to go with your other 6.5 inch squares.

The best investment I made is for a 6 1/2 " square ruler. I once thought only purist cut the triangles 6 7/8 for accurate 6 1/2: squares and then realized my time is worth more than the sliver to cut off. Makes more accurate 6 1/2 square blocks.

Lots of HST discussions this weekend ...
http://www.quiltingboard.com/main-f1...s-t185211.html
http://www.quiltingboard.com/main-f1...t-t185374.html

For many of us, it's easier and less aggravating to cut down an 1/8 of an inch on a slightly oversized HST unit, than it is to end up with a skimpy HST unit.

Try cutting a 6.5 inch square diagonally and sew it back together - then one understands what happens!!!

I am a newbie quilter and I also have a pattern that calls for 7 inch blocks for 1/2 square triangles. I have a 6 1/2" square ruler but I never used it. How would you go about using it? Turns out that I cut out the 7 inch squares and sewed 1/4 in. on each side - ironed each square. One square came out 6 1/2" but the other one had to be trimmed to 6 1/2". The pattern is called Flying Geese. I thought you needed a special ruler to make Flying Geese triangles.

No special ruler needed to make flying geese.