What does ‘shadow show through’ mean…?

Shadow show through on umbrella means an effect that looks like the print is a shadow, rather than directly printed onto the panel of the umbrella. The design shows through the fabric in a non-traditional print method. Umbrella material is thin and translucent. Shadow show through refers to a technique of using 2 pieces of material, printing on one of them and allowing the image the show through, creating a pleasant visual effect.