How can I store merchandise products metadata?

Most clients create their merchandise items as Releases because the Release Catalogue Type offers the option to store both Catalogue Numbers and Barcodes. Additionally, a Release can store Distribution Channel and Format/Configuration information, which can be used to indicate the type of item (e.g., T-shirt, Poster) and its specific variant (e.g., size or colour). These specific variants can also be stored in the Version field.

For more information please review: How to Add Tracks & Releases