Neither. Taxes are calculated on taxable income, which is what's left after you've subtracted all expenses and depreciation applicable to your business. If a purchase is required by the guidelines and you are subsequently reimbursed for the purchase, the reimbursement is not taxable because the original expenditure was a shop expense that was required. Your taxable income from your business is calculated on Schedule C and the result is added to your Form 1040.
The best sources of tax information are the website IRS.gov and your tax professional.
Mary Davis Nowell. Based close to Fort Worth. Shopping Interstate 20 east and west, Interstate 35 north and south.