I am building structured data sets for my artist studio. We sell lighting / vessels, but not from these web pages (from the store page only).
These pages are about specific products, but with no e-commerce attached.
Should I be listing them as "type": "ItemPage" and use keywords then? I noticed "Product" doesn't offer keywords.
Thank you.
I think ItemPage and Product are at different levels. The first provides information about the WebPage (its a sub class of WebPage), and the second is about the entity (item) that is on the WebPage.
So I would say you could define both with Product being the mainEntityOfPage for ItemPage.
You probably want to stick with one official page that defines the product. Or at least, use the same id for every time you mark it up. So if the product is also marked up on the ecommerce site, you probably want to use the id for that entity so that it is clear that you are talking about the same thing.
The Structured Data General Guidelines of Google requires to ensure that the structured data represents the main content of the web page to which they refer.
In its turn the guide of Google for Product informs us:
Use markup for a specific product, not a category or list of products.
and
a product page that describes a single product.
Thus, if you are creating structured data for a web page that has a main content sush as description of the product, then in this case you can use the markup for the type Product.
If your web page has a list of products or categories, then it may be useful to use markup for type ItemList as Google suggests.
Creating markup for the type Product has no connection with e-commerce. This can be used to mark up the products of a physical store website.
