Thanks for your advice and suggestions. I double checked and I did have all the measurements correct, so I did a little head scratching and gave up on my original plan. I decided to attempt the applique route as I'd never done anything like that before. I watched the Debbie Shore video as
@wrenkins suggested and managed to complete it with varying results.
I discovered that you need to be really accurate with the cutting and ironing back the seams - one side of my rectangle was square and the other turned out a little wonky. I'm not sure if I wouldn't have achieved the same results by placing the butterfly material on top of the purple material and stitching it on, using the same stitch, hence reducing all the preparation work sewing and cutting out the hole. Maybe as I'm using a flat piece of cotton material this wouldn't have made much difference, but if I was using batting etc the applique effect would be more visible :thinking:
One quick question, are you supposed to be able to reverse in any stitch settings on the sewing machine to secure the threads at the beginning and end of sewing? Mine didn't like doing it very much in the short zigzag I chose...
As per some recommendations, think I'm going to have a go at making a bit of a patchwork/quilt piecing cover for my stool instead. Wish me luck! xx