I had the same problem, this is what I did, unfold fabric (as it comes off the bolt), take your 6.5 inch ruler and use it to fold the fabric around it, kind of like circling around the ruler. Once complete, slide the ruler out and fold in half. Sort according to colours, looks very impressive, I will try to attach some photos. Hopefully this makes sense,
Before
[ATTACH=CONFIG]197709[/ATTACH]
After
[ATTACH=CONFIG]197710[/ATTACH]