Shopify Flow is one of the most powerful apps on the market, and it's completely FREE!  What makes it so powerful is that you can use it to automate "if this then that" type of tasks.  Things like "assign products to a collection" or "add tags to a customer", here are a few pre-built Flows that we find useful (you can download the flow and use the Import feature of Shopify Flow to import the flow into your Shopify instance).

Download Shopify Flow from the Shopify App Store

Use Shopify Flow to Assign Products to Tax-Exempt Collections

Download the Flow here - Assign Products to Tax Exempt Collection

In order to use Tax Exemptions (in regions where Shopify Tax is not available), you'll need to create a manual collection and assign items to that collection. - See Shopify Tax Overrides and Exemptions.

Here's what this flow looks like.  We start when a product is created, check that the Product product type is equal to Graphic Novels, add that to your collection (you will have to edit this part).

If no type is found, send an email to the store to let them know that a product is missing a product type.

(1) - Choose your manual collection (see Shopify: Creating a Manual Collection).  I named mine "HST Exempt"

(2) - Next we'll replace the email and the URL of the store with the correct info.

(3) - Enter the email you want notifications to go to in the Email Address field

(4) - Update the URL in the with the URL of your store admin.

Find your store URL in the address bar of any page in the Shopify Admin.

Turn on the workflow (upper right hand corner)

Download the Flow here - Assign Products to Tax Exempt Collection

Once you've configured and started the flow, you can test it on any product in your store.

(5) from a product, select More actions.

(6) Select the "Assign products to Tax-Exempt Collection" workflow

(7) Click the Run Workflow button

(8) View the Results in Flow

(9) Flow shows you what it did recently, and if it did something, it will let you know (since this was a comic, the results were "none".