You can but that can be bulky
... if you are really careful, you can undo them, and just have a single thread to weave in later.

I'm so glad you asked that question! I love filet crochet, too, but it's been awhile. I couldn't remember how I figured out the base chain for patterns I made up. Thanks for the reminder!

Back when I used to crochet, I made a lap quilt out of regular three ply yarn, from a filet crochet pattern for a placemat. It turned out beautiful, but it will always remain a one off because I quit crocheting soon after when the symptoms of carpal tunnel started. All I remember is it had roses on the center and a swirl down each end, done in a soft peach color. It can be done.

I use to do a lot of thread crochet. I was an avid follower of the original Annie of Annie's Attic Crochet. I never count the stitches on the foundation row only the second row. I used a separate skien ( or cut and make a small ball of the thread) to make the foundation row and separate skien to start the second row. If I need more stitches in the foundation row it's easy to add more or easy to ravel out the row if I have more then I need. This makes the foundation row so much easier. Who wants to count stitches over and over on that first row especially when doing thread crochet!

Onebyone that is genius! Thank you so much! Such a simple way to save so much time and frustration.

What a great idea!!