Shop supplies and waste-handling charges can be calculated using percentages that you specify.
You can't forget to charge for them because it's done automatically.
You can specify that a particular invoice not have shop supplies and/or waste handling charges if you wish.
Shop supplies are based
on a user specified percentage of the invoice labor charges.
Waste handling is a specific dollar amount.
You can place a cap (maximum) allowed amount on shop supplies. Like for example, if you don't want to ever charge a customer more than $15 for shop
supplies, you can set $15 as your maximum allowed shop supplies.