Thanks everyone! My instincts were that the tax would only apply to money that I received, too. But as I was laying out the 'Certificate' I started to put the disclaimer 'does not include Sales Tax, framing, shipping or travel expenses' from my fee schedule and that got me thinking... will contact the state to confirm how this works and if I get a response, will pass it along. . .
Something else I've been stewing on is what if something were to happen to me that made it impossible for a donation to be redeemed (o.k. admittedly morbid, but possible
)?... Presumably the donation's purchaser might have paid a fair amount for it... with nothing to show for it, since I am a sole proprietor, are they just out of luck? Would my 'estate' be liable for it?