Why Aren’t My Quilt Blocks The Right Size

I get this question almost weekly. “Hey Mel, I am making a quilt and my blocks are supposed to be 12 inches but they all come out at 11 and 3/4 inches. What have I done wrong?” It’s almost impossible for me to give a direct answer. There are too many causes to pin point it. When Paul asked me why his quilt blocks didn’t come out the right size the other day I got a few more grays but went through the list with him until we realized what the cause was. I realized it was time to just write out all of the reasons once and for all.

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The first thing to check is did you cut the fabric the right size? It’s easy to goof a cut, read a pattern wrong, or pick up the wrong pre-cut package. Another thing that can happen when cutting fabric is where you line up the fabric on the line of the ruler. If you use a ruler with really thin lines you probably won’t notice a difference. If the lines are thicker than a pencil line that is enough to throw off a block. If it’s any of those things you either have to roll with the mistake or start over. Fabric cut the wrong size can’t be fixed without starting over. I wouldn’t start over, I would leave them. If I had to have a bigger quilt I would just add another border.

The next place to check is your seam. If your seam isn’t right, check out Paul’s post on a variety of ways to get a perfect quarter inch seam. Once you know how to get your seam perfect you’ll have to rip out all of those wrong ones. Ripping can be a pain so I have tips to make ripping seams out painless.

The thread can change the size of your block. I know that sounds crazy but it happens. If the pattern writer was using say a 50 weight thread and you used a 30 weight it will change your block size. The 30 weight takes up more space and I know it doesn’t seem like a lot but a little bit adds up over an entire block. If it’s a block with a lot of seams it can dramatically change the size of your block. A thirty-second of an inch adds up over time. If you have four seams that’s an eight of an inch that you are off.

The last thing is pressing. This is kind of like the thread thing. It doesn’t take much to add up. A smidge of a tuck or not as flat as it should can throw you off down the road. You can always repress and see if it helps. It may or may not help. Some times you think it is the pressing but it was something else like the thread.

So what can you do? Well like I said at the fabric you can start over, either recut your fabric, rip all those seams out, use a different thread, or repress every block. I wouldn’t. I would just roll with it and call it a design choice. No one will know that the blocks were supposed to be twelve inches and they turned out eleven and three quarters. If I need the final project bigger I just add a border. If my quilt blocks went too big I just let it be bigger. No one has ever complained their quilt was four inches too wide.

So why were Paul’s quilt blocks the wrong size? Well, partly it was my fault. He’s sewing a pattern up for me and in my design, I didn’t leave any room for squaring up. If everything goes right then there’s no need to square up. When was the last time everything went right in quilting though? Another part had to do with the thread thickness. I am pretty sure the software I am using assumes you use 50 weight thread but he was using a 30 weight thread. The other was the cutting. Paul normally uses a ruler that the lines are like pencil lines. They are very fine but he used a different ruler with thicker lines. I consider them normal. When he cuts he lines the edge of the fabric with the right side of the line and I go to the left side of the ruler. If you know anything about woodworking it amounts to taking the line or leaving the line when you are cutting wood.

As a pattern maker, I don’t know what thread you are using, I don’t know how you are pressing, or if your seams are perfect. You know what else? I don’t care. If you are happy with the final project that’s what matters. I will never know that your blocks turned out a different size. Even if you send me a photo I won’t know unless you point it out. Guess what? DON’T POINT IT OUT!!! No one needs to know and if you don’t tell they won’t know.

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why are my quilts the wrong size

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