Yes you put materials under Supplies. Or if you don't like Supplies then use line 27 for Part V Other Misc Exp.
See Schedule C instructions for line 22.....
In most cases, you can deduct the cost of
materials and supplies only to the extent
you actually consumed and used them in
your business during the tax year (unless
you deducted them in a prior tax year).
However, if you had incidental materials
and supplies on hand for which you kept
no inventories or records of use, you can
deduct the cost of those you actually
purchased during the tax year, provided
that method clearly reflects income.
https://www.irs.gov/pub/irs-pdf/i1040sc.pdf
