draw designs on the fabric using the sharpies.
This information suggests that permanent markers will wash out over time and turn yellow. You might consider permanent "fabric" markers instead Deirdre!
Sharpie makes a special "stained" version for fabric. It resists fading after normal washing. https://www.sharpie.com/markers/art/stained-sharpie/SHStainedBlackBrush
Make sure you get the type for fabric and then you can draw/dolor onto any fabric.