I want to share a little tip with y'all. I've recently been using Frixion pens as a marking tool and they are really neat.
I heard about them from other corsetmakers who use them to mark bone channels and seam allowances. They aren't designed as sewing tools, but as erasable gel pens. They erase from the heat of friction, which means the heat of an iron makes the ink magically disappear.
See what I mean:
Here I've drawn a straight line with the blue pen on some scrap white coutil. I've been using this to mark the stitching lines for all the channels on my 18th century corset and it's really useful.
And here's what happens when you hit it with an iron. It's instant, so you have to be careful if you're ironing something and don't WANT to erase all your lines yet.
And here it is completely ironed. You can see the ink totally disappears. Here you can make out the white line where it was, but it's not something you'd spot from any distance and it doesn't show up on most fabrics. Always test your fabrics first, of course.
The only problem with these is they don't work on black so I still have to use chalk a lot of the time.
I also was recently making some little storage bags and realized how super useful they were for marking all the pocket lines and zipper lines, etc. So I thought I'd share since they are so useful for all kinda of sewing.