I'm thinking perhaps you are going just a bit deep with your overcast stitch. I use the same color thread for all my EPP, and it does not show thru. Besides, in your case, you have to use either black or pink. Will show on one of the other unless your stitches are smaller. You wouldn't use a running stitch with EPP. That is done without the papers. When basting to the papers, I use one fairly large stitch on each side. Double stitch at the "corners" When I remove the papers, I do not have to remove the basting. I clip that one stitch from the front, turn it over and pop out the paper from the back. That brings the thread to the back. That one stitch stableizes the fabric, and keeps the papers in until I want them removed. I use a light color thread for basting and overcasting. My fabric is usually starched before cutting, but I don't starch after, nor do I press each basted hex. Just take your time. and it will get better with every stitch your take. Good luck, and have fun with your project.