As an upholsterer I buy fabric and other supplies to finish the piece I am reupholstering, where would I claim those supplies?

According to the Canada Revenue Agency (CRA) Office Stationery and Supplies (Line 8811) is where you can deduct the cost of items your business used to provide goods or services. So, if you didn’t include these items in your cost of goods sold, then Office Stationery and Supplies would be the place where you would claim those things.