update: Why not use wtaer soluble pens? I have had never bad experiences with it, wash it with lukewarm water - but be sure you make your floss colorfast at first (before you stitch) so they won´t bleed ... As you mentioned, I grid only a little part at first, in little projects. In bigger ones I use a thread called easy guide, bright orange in color, you can reuse it after finishing your work and it is easy to pull out of the fabric! Takes a little time but absolutely worth! But anyway, the most important thing of XS is having fun =)
chekccard