1. A computer-implemented method for combining a digital product image with a digital design image to create a blended digital image indicating the appearance of the product after the digital design image has been printed on the product, the method comprising the steps of: creating, by one or more processors, a modified design image by, for each pixel of at least a portion of the pixels in the design image, (a) reducing an alpha value associated with the pixel and (b) modifying a color of the pixel by determining a lowest component color value among component colors of the pixel, subtracting the lowest component color value from each component color value of the pixel, and dividing the result of the subtraction step for each component color by the reduced alpha value of the pixel to determine modified component color values for the pixel, and generating, by one or more processors, a blended digital image by combining the modified design image with the digital image of the product.