I have found pencil doesn't always wash out. Sigh, it wasn't a happy time.

I use the new Crayola product of fine tip washable markers. They come in the 8 major colors. I used them on my quilts and they have washed out fine. Remember that you shouldn't iron over any marking because that sets the ink! I use cool water even thought the box said warm to hot.

i left some in a long time and soaked the quilt in Oxy clean, rubbed the lines a bit too. they came out. i never use the pencils now.

I use the Fons & Porter mechanical pencil. It comes with dark and white lead. It works well, and washes out

I used the fons and porter lead and it didn't wash out.