Create a Base Product

To create a base product, you create a base product first, then assign variation products to it.

Select Merchant Tools > Products and Catalogs > Products.
On the product search page, click new.
On the Product page, select the General tab and complete the product details as desired. Make sure that the Online and Searchable options are set to Yes.
Select the Categories tab and click Edit Categories.
Expand to the category where you want the new product variation assigned, and click Apply.
Select the Inventory tab and select the site to which you want to allocate product inventory and click Create.
Select Perpetual.
Set the Allocation amount and click Create.
Click Back.
Select the Variations tab, and assign variation products to the newly created product.

Note: For the base product to appear as a base product in the product list, you assign variation products to it.