Store: Selling hundreds of products?

I'm kind of lost about setting up a Store Page to sell hundreds of hardcopy photographs in a variety of sizes and finishes in different categories of image (landscape, floral, animal images...that sort of categorization). As I currently understand the process, each photograph constitutes one unique item. Is this correct? I assume by using 'forms' one could have a customer choose different print sizes and also different finishes, but that still means a separate listing for each and every print?

I haven't found a site or youtube video that adequately answers my question, so I am looking for help from you, the informed squarespace web community.

Thanks.