Seam allowances help make a shirt, skirt, or other item to fit and hang nicely. Most patterns give you a suggested seam allowance, but there are times where you might want a bigger or smaller seam allowance. You might want to use a slightly smaller seam allowance if you are large in an area, so that the fabric doesn’t bunch or make you look bigger. On the other hand, you might want to use a bigger seam allowance if you are small in the same area so that you don’t look quite so skinny. Another reason you might want to use a bigger seam allowance, if you want an outfit to last longer because then you can let the seams out as you grow. Also, you might want to use a little bit bigger seam allowance is to accommodate if you are adding lace or other trim into a seam. The one thing to remember is not have your seam allowances way to big because it make your clothes hang poorly and also it adds a lot of bulk. It is better, though, to have your seam allowance a little to big rather than a little too small. This way if you make a mistake, you can correct it. If the seam allowance is too small, you run the risk of not being able to wear the clothes or fix them.