I had the unfortunate experience of finding this out the hard way. I used the regular pounce pad chalk in blue and it did not wash out. Even after 3 washing I could still see a bit of the blue. The worst part was the peely-balls that developed after the multiple washings. I think I can blame the Connecting Threads fabric for that :(
Originally Posted by Holice
For the regular chalk pounce. I have seen it demonstrated by pouncing and then spraying with hair spray to fix the chalk until the piece is quilted and washed. I don't remember if it can be brushed off and not have to wash or it must be washed out. Regular pounce chalk - and even the colored chalk will bounce off in the work. And I would not recommend some colors because they may not come out.
If chalk is used then I recommend that as much of the surface chalk left be removed with brush or dry terry cloth before washing because chalk will cake and may be more difficult to remove.