And down here at the low tech end:
I use crayola washable markers. That's pretty low end. I know I'll soak wash my quilts when I'm done so using washable markers is not a big deal. There is a large BUT coming up:
BUT I buy Crayola Washable Markers 2-3-4 boxes at a time so hopefully they will all be from the same manufacturing batch. I test one of every color (only 8 so it isn't difficult) and keep only the colors that washed out completely and give the rest to a third grade teacher I know who is happy to have whatever colors I don't want.
I found Moda fabric to be the one most likely to grab the Caryola Washable Marker and not let it go so now I rinse Moda in hot water and let it drip dry before using.
I think part of your question was about matching up corners and stencils and I think I have some stencils that came with fancy corners and you somehow got a chance to fudge the long lines or the fancy corners to adjust the corners? That ring a bell with anyone?
Jois