Show product Category info in Cartthrob Order Notifications emails

For anyone else who’s been struggling with displaying an Entry’s Category data, in Cartthrob’s order notification emails… here’s the solution I’ve found that works.

Order Notification Template
Where you list the items in he order:

{order_items}
       {item:title}
       {embed="notifications/new-order-customer-embed" item_entry_id="{item:entry_id}"}
{/order_items}

Embed
This retrieves any of that item’s Category info you need (standard or custom Category fields):

{exp:channel:entries channel="products" entry_id="{embed:item_entry_id}" dynamic="no"}
       {categories}
              {category_name}
       {/categories}
{/exp:channel:entries}

Hope this helps.