There are marking pens that disappear on their own in a short period of time. They are readily available at LQS, internet shopping, WalMart, etc. Just read the packaging. One thing to beware of tho- the chemicals from the ink are still in the fabric- it could cause troubles later??? Don't use them myself- the chemical residue thing and they disappear too quickly for me (usually from 15 minutes to an hour or two depending on how heavily it's marked, humidity, type of fabric and several other factors). Maybe a Chaco-Liner or other chalk method would be better? The chalk brushes away easily with no residue.
Leslie & The Furbabies in MO.