Inklingo by Linda Franz. If you are not familiar with Inklingo, click on the link and go over and have a look around her web site. It really is pretty amazing. There are some free downloads on Linda's site that you can try out. With Inklingo you iron freezer paper to the right side of your fabric and then run it through your printer. The cutting lines, sewing lines, and cross hairs to match your pieces all print on the back of your fabric. I have a couple other Inklingo downloads, too. My POTC blocks are sewn by hand. The half square triangle Inklingo is just great. You print on your light fabric and then put it right sides together with your darker fabric, sew on the lines, and then cut apart. I machine sew the half square triangles. It's really quick and easy.
Here's a bit closer at the fabrics that have been printed.
I have a few more block kits all prepped and ready to sew.