Gorgeous fabrics and colours! Beautiful and will make lovely dresden plates!
I prewash all my fabrics as this was what I was taught to do when I first started with patchwork and quilting. I have had 'bleeds' in the past and come to regret not prewashing my fabrics. Come to think of it, the 'bleeds' were not from batiks either!.As a precaution I wash all my fabrics as I cannot bear to find a 'blotch' after all my hard work!
It's a pain but well worth it at the end! I have never used starch so cannot offer any constructive advice. Best wishes and enjoy!