Oh, yes, they are if they were for business. I have written off a ton of bizarre things on my taxes as a writer.
Consultant fees for a trapeze artist
fused glass-making classes
software for keeping track of word count
corsets, hats, and a very sound of music costume that was meant to be steampunk and ended up more yodeling clothing
mini corn dogs, chip and dip, and redneck wineglases (That was a disaster)
which reminds me, FedEx never got back to us on our claim. Hmm.
and that doesn't even begin to cover the things I've bought for gift baskets and giveaways
That's a whole 'nother post