Hello LInda, We stitch all of our designs and had no problems but I would never put a design on a costume or piece of clothing without doing a test stitch. Different fabrics, threads, etc can make differences in how designs stitch. If you decide to do this, use a piece of fabric the same or as close as possible to your costume. thread colors don't make a difference. it's just to make sure it doesn't pucker or have gaps anywhere. The thread we were using when we did the owls is no longer being manufactured. Because I loved the colors so much I eventually came out with my own brand of thread and duplicated many of those colors. Did you download the colorchart.zip file? You need that for the order of colors for each design. There is also a conversion chart to many brands. If you want our thread, you can get a conversion chart at the very bottom of the home page. I looked at our website - gorgeous!!!! I have especially always loved the celtic music, dance, etc. I might have to get your book. :) I'm going to have another look! Thank you - Suz