1. A computer-implemented method, comprising: causing, by a server computer through a display of a specifying system, display of a product image depicting a customizable product; after causing display of the product image depicting the customizable product, receiving, by the server computer from the specifying system: one or more attribute location inputs, wherein each attribute location input identifies a location within the product image that does not include the entire product image; and an attribute definition for each of the one or more attribute location inputs, wherein each attribute definition defines a customizable attribute associated with the respective attribute location input and a set of customization options available for customizing the customizable attribute associated with the respective attribute location, wherein each attribute definition defines whether a design input is enabled for the set of customization options available for customizing the customizable attribute, wherein the server is configured to generate an interface for a client computing system to provide a design for the customizable attribute if the design input is available; and in response to receiving the one or more attribute location inputs and the attribute definition for each of the one or more attribute location inputs from the specifying system, storing, in volatile or non-volatile storage accessible by the server computer, customization information, wherein the customization information associates the locations specified in the location inputs with attribute definition information included in the respective attribute definition.