In order to save the Product in Shopify, I had to enter an SKU. I entered just 0 for every variant that did not have an SKU and was able to save the product in Shopify. Then I went back to Printful and the product overview said there are 10 unsynced variants. I edited the product in Printful and added the according printful poster with frame SKU best practices. Characters in SKU numbers can represent information such as manufacturer, color, size, cost or warehouse location, etc. However, if you try to pack too much information into a SKU number, it can become long, confusing, and create a greater risk of data entry errors or packing and shipping errors. The first six digits of the UPC are the manufacturer. The next five digits are the product item number, while the last digit is the check digit. It’s generated by adding and multiplying digits in the code to confirm the UPC is valid, otherwise, it won’t scan properly. When you’re adding your product to Amazon, you’ll need the UPC or A SKU (Stock Keeping Unit) is a unique alphanumeric code that's used to identify a product or variant of a product, based on details such as its model, size, or color. SKUs can vary in length and can include letters, numbers, or both. SKUs are used to distinguish product variants, track inventory, and ship the right item to customers. For newly created products, the product status is set as Active by default. For duplicated and unarchived products, the product status is set as Draft by default. You can set the following statuses: Active: the product details are complete and the product is ready to be sold. Draft: the product details need to be completed before it can be sold. UCZEC65.

how to set up sku numbers