using a pair of tweezers to hold it, carefully cut into 8 equal squares. that's how i've always done it. try your best to not have to touch it with your skin, because it will damage the blotter.
if its just for cutting don't worry about too much, it won't do too much damage to the blotter. You will absorb some lsd but not in such of an amount that you trip balls. It probably wouldn't even be threshold. but on the safe side, use tweezers