It is difficult to give an informed answer without knowing some identification of the source. The comments so far appear to be giving all preprints a bad name which is not true. I do know there have been some commercially preprinted panels that were never to be washed out. Your description sounds like it might be one. The printing process does not allow for both colorfast and wash out in the same process. A second run thru would have to be made. So my guess, and it is a guess the quilting lines were permanent contrary to what the shop owner told you. So unless we can identify this product please don't guess the answer which might be incorrect. There are many preprinted products on the market that do wash out. Most of these are because of human error if they don't wash out.
I just received the current Keepsake catalog which has two of the preprinted whole cloth queen size (Page 73). These are printed with wash out ink.
Last edited by Holice; 11-12-2013 at 04:26 PM.