showthrough

Showthrough is a term used to describe the visibility of material or markings from the reverse side on the visible side of a substrate or fabric. It reflects the degree of transparency or translucency and is generally considered a quality issue when undesired.

In textiles, showthrough refers to the extent to which the color, pattern, or texture from the back side of a fabric becomes visible on the front. It is influenced by fabric weight, weave, fiber content, finish, and construction. Light-colored or lightly woven fabrics are more prone to showthrough. Measurements of opacity or transmittance are used to assess and compare fabrics, and common mitigation strategies include choosing heavier or denser weaves, adding lining or backing, or selecting fabrics with tighter constructions or non-representative finishes.

In printing and paper production, showthrough describes ink or toner that transfers or appears on the opposite side of a sheet, reducing legibility or legibility of the primary side. It is closely related to opacity and is affected by paper thickness, finish, absorbency, and ink density. Designers and printers aim for adequate opacity through selecting appropriate paper grades, coatings, or double-sided printing techniques to minimize showthrough.

In other contexts, showthrough can describe ghosting or faint imagery that appears on the opposite side of a surface due to diffusion, layering, or residual marks. Across disciplines, it is typically viewed as a perceptual or quality concern, balanced against cost, design goals, and material performance.

See also: opacity, translucency, transparency, translucency testing.