Lady Diana

You don't have to mark your quilt top for cross hatching or put masking tape down dozens of times ....only once. Most machines have a "bar" that fits into the presser foot holder. Put masking tape down once at the angle you want on your quilt top. Or you can draw one faint line on the top. Use the "quilting bar" to guage where your next line will be with the bar on your first line of stitching.

msarANG

It may be a little bit offtopic, but my daughter loves use hera marker for quilting and handcrafting. Sometimes she uses hera marker to mark straight lines on a fabric(sometimes even on a thin leather) before embossing letters or making die cutting(we bought Sizzix Big Shot for her, which is very good btw) and it works just fine depends on lighting. Not great, but fine.

Onebyone

I always wash my quilt when it's finished regardless of size.

Jo Belmont

The Crayola Ultra Clean Washable Markers are my go to in just about every situation. They are inexpensive, I've never found a color that doesn't readily wash out with any temp water. Not a problem for me as I always wash my quilts when they're done. Besides getting out the marks, it seems to "settle" all the stitching, batting, etc. and the quilt looks lovely and I can gift it knowing there won't be any surprises when it's washed.

P.S. I understand old eyes. I'll be 80 in just a couple weeks.

Flyboy Jim

Lately, if I'm going to be quilting with cross hatching, which I do a lot, I lay the quilt top out and mark the cross hatching with a black Frixion pen for light fabric and a white chalk pencil for dark fabric. Doing this before assembling the quilt sandwich works much better. If I was going to be doing a close cross hatching, I just mark every few inches apart and then do in-between with the guide on my walking foot.

Jim