CosnignCloud allows you to have certain items with no tax payable attached. This can be both a store-wide policy or just the occasional tax exemption for unusual merchandise.
Making an item tax exempt
In order to make on item tax exempt, simply click on "Advanced Options" as you add or edit the item.
Directly above the "Title" field, check the box that "Disable sales tax on this item."
Setting up tax exemption as the default
In order to have all your items entered by default as taxed, go to "Settings".
Under "Store Policies", below the tax rate, check the box that says "Disable sales tax rate by default when adding items."
To override this, simply uncheck the box when adding an item under "Advanced Settings", as above.