Dry Wipe Character Cards
Rather than paper sheets, new boxed sets will come with A6-sized dry wipe cards. You can still print your own sheets, obviously, but these will provide a reusable alternative.
They’re laminated on one side and they work with any dry wipe pen — or even felt tips.
I would recommend the Staedtler Correctable pens (available from All Rolled Up, along with all the in-print books for The Cthulhu Hack), but you can use whatever you have to hand.
They’re available from the All Rolled Up store, £5 for a pack of 10.