thepolyparrot

I love Fabrico dual tip markers - one end has a fine point and the other is a brush tip. They're permanent and they come in handy for all kinds of uses in sewing.

You can buy them individually or in sets: https://www.dharmatrading.com/marker...c-markers.html

Identi-Pen is another marker that works well and is permanent, but they don't have as many colors.