Shopify currently limits us to 100 variants per product listing. For example, a small black Gildan 5000 cotton t-shirt is considered a variant. A medium black Gildan 5000 cotton t-shirt is another variant. As you add different size and color options, the variants can quickly accumulate, especially when you are creating a grouped listing.
If you try to publish more than 100 variants for a product listing, Fuel will display an error.