I use pencil all the time and I never had a problem. Make sure to mark lightly. Also, after I wash the quilt, I check it closely to be sure the lines are gone. If they are not, I put some laundry detergent (liquid kind) directly on the places that still have marks and rub gently (like you would on regular laundry to get out stains). Then I rewash and check it again. The most I've ever had to wash was 3 times and that was because I marked too heavily. Once the marks are gone, toss it in the dryer.