Strike-Through Errors: Foreign Material Impressions on Coins

Strike-through errors occur when foreign material gets trapped between the coin die and the planchet during striking. The material leaves its impression, shadow, or void in the coin's surface. Strike-throughs come in more variety than almost any other error type — from common grease fills to rare and dramatic cloth or wire impressions.

What This Means

During coin production, the area between the dies should be clear. When debris enters — grease, metal fragments, wire, cloth fibers, or other material — it interferes with the design transfer, creating a strike-through. The nature of the impression depends on what material was present.

What to Look For

• Smooth, flat areas where design detail is missing (grease fill)
• Linear marks from wire or thread trapped during striking
• Fabric weave texture impressed into the surface (cloth strike-through)
• Impressions matching the shape of identifiable objects
• Foreign material still embedded in or adhered to the coin
• Sharp boundaries between affected and unaffected areas

Common Mistakes to Avoid

• Confusing wear with grease-filled die errors — wear follows high points gradually, strike-throughs have sharp boundaries
• Assuming all missing detail is a strike-through — some coins were simply weakly struck
• Not examining under magnification for texture clues
• Overvaluing minor grease fills that are extremely common
• Confusing environmental damage with strike-through impressions

What Affects Value

Strike-through values vary enormously by type. Minor grease fills carry little premium. Identifiable object impressions (cloth weave, wire shapes), large affected areas, and retained foreign material significantly increase value.