Hello All,
I need help in explaining what I need to increase my cuts for a 1/2 in seams.
You see, Every quilt I have made in the last 2 years (using the 1/4 inch seam allowance has become unstitched.

I have used 1/2 inch seams before I joined any quilting groups and learned that Quilts should be made using 1/4 inch seams.

When I complete my quilt, I tack it every few inches to keep it together.

If I am making a 4 inch block using half square triangles do I increase my cuts to be 1/2 inch larger than the instructions call for?

Can someone please shed some light?
Thanks in advance, Laura A in Brick, NJ

Perhaps your stitch length is too long. Did you try shortening that to see if it creates a stronger seam?
Also, what is the quality of the fabric you're using? If it's very thin, with a light weave, that could be part of the problem.

I'd be really surprised if increasing the seam allowance size (and therefore EVERY single measurement for everything you're going to sew quiltwise) is the ONLY solution.

like mts said, you may need to shorten your stitch length. also try backstiching the beginning and end of each seam. That said, If your piece is to finish at 4 inches with a quarter inch seam you add a half inch (2 times 1/4). If you want to use half inch seams you would add 1 inch (2 times 1/2). When you increase the seam depth you add extra weight and bulk to your quilt. this will make it more difficult to hand quilt, and could cause problems even machine quilting.

go back and try to discover why your seams are coming apart. I don't believe making 1/2"{ seams is the solution. You will have real problems when putting different shapes together However, If I were doing it I would draw the finished size of the shapes on graf paper and then add the seam allowance and then measure to determine cutting. as long ss you are making squares and rectangles there should be no problem. the problem is when doing triangles and diamonds.

on another note. If they don't hold at 1/4" they won't hold at 1/2" Sounds like it is your stitch length or the quality of the stitching.

Agree with everyone above, the time I use 1/2"is. On flannel.

Seams coming undone?

Before enlarging your seam allowance, check:
1. stitch length, make it shorter

2. tension is off on your machine stitch

3. thread quality, older thread often weakens especially if exposed to light and air

4. fabric easily frays (not quality100% cotton)

5. quilt is not quilted close enough together when finished, use the width-of-your-hand rule

Jan in VA

how old is the thread you're using? IF it breaks easily by hand, it's not good to use for stitching. Also, what is the weave of the fabric you're using? Loosely woven fabrics may well fray out if only a quarter inch seam is used. Tighter weaves should hold stitching with quarter inch.

i also agree with finding the problem But to answer the question i think if you add 1/2 inch to all measurements that should give you the extra for seam allowance exmpl 2 inch square would be cut 2 1/2

Another thought is, are you chain piecing? If you are snipping each time you add a piece of fabric or not starting from the very beginning possibly with leaders and enders you could be weakening your pieces.

Checking your stitch length sounds like a good idea, and also when it comes time to quilt, dense quilting will help to strengthen your quilts.