Simple Theme - Product image custom labels
From Spiffy Stores Knowledge Base
By default, your Simple theme supports three types of Product Image labels — FEATURED, ON SALE and SOLD OUT.
It's possible to add your own custom labels to support any type of promotion that you want for individual products.
Create a Product Tag
Create a product tag with the following format to add a custom label to the product images.
label:label text
Some examples are:
label:new release label:limited offer label:as seen on tv
Create the product tag on each product that needs to feature the custom label. You can create more than one custom label for each product.
Add the Product Tag to multiple products
You can add one of more Product Tags to a number of products at the same time. This can be done from the Products overview page, using filters or search terms to selct the products that you want to tag. Once you have created the list of eligible products, simply select them all and from the popup action menu, select "Add tags" to add a new or existing product tag to the list of products.
Similarly, you can delete one or more tags from a list of selected products.
Once the custom tags have been added to a product, the product images will now display the custom labels that have been derived from the product tags.