Casein Button Value Guide

This Italian-made Casein button from the 1930-1950 era represents a pivotal moment in early synthetic plastic history. Highly collectible for their unique origin as milk protein treated with formaldehyde, these buttons were prized for mimicking expensive natural materials like ivory and bone.

What affects the value of Casein Button?

• The specific Italian origin and 1930-1950 production era significantly influence the $2.50-$2.75 price point.
• Condition of the concave center and the preservation of the original cream-colored dye.
• The presence of original thread remnants, which can indicate the button was salvaged from a period-correct garment.
• Market demand for early synthetic plastics and precursors to modern polymers.

How to Identify Casein Button?

• Look for a cream-colored, circular form with a slight concave center and four distinct thread holes.
• Examine the material for a dense, matte texture that resembles natural bone rather than modern lightweight plastics.
• Check for a subtle 'milk glass' translucency when held up to a strong light source.
• Identify authentic vintage wear, such as the presence of original thread remnants in the center holes.

History of Casein Button

Casein buttons, often referred to as milk glass or early synthetic plastic, were popular in the early 20th century. They were created by treating milk protein with formaldehyde to create a durable, moldable substance. This material was a precursor to more modern plastics and was widely used for garment fasteners due to its ability to take dye and its resemblance to natural ivory or bone.