Copper Plaques
The most dramatic transformation in metalwork. Pure copper begins as warm rose-salmon and evolves over centuries into a rich green patina — a living, breathing record of time that no other material can replicate.
Copper Plaques
C110 · ASTM B187
Copper Plaques
What Is C110 Copper ?
Our copper plaques use C110 electrolytic tough pitch copper — the purest commercially available copper alloy at 99.9% copper content. Also designated ETP copper, this is the benchmark for all other copper alloys and has served artists, architects, and metalworkers for millennia.
What makes copper exceptional for plaques is not just its purity — it is the way it changes. Copper undergoes the most dramatic and beautiful aging process of any architectural metal: from fresh salmon-pink, through warm browns, into the iconic blue-green verdigris that defines the aesthetic of time itself. The Statue of Liberty. The rooftops of Copenhagen. The spires of European cathedrals.
Indus Metal Plaques crafts C110 copper plaques for clients who want a piece that lives and evolves — growing more distinctive and irreplaceable with every decade of exposure.
Alloy Composition by Weight
Why near-pure copper? The 99.9% copper content means the patina that develops — copper carbonates, sulfates, and chlorides — is authentic, vivid, and irreproducible by any alloy. Lower-purity copper alloys produce blander, less dramatic patinas. C110 ETP gives you the real thing: the same chemistry that turned the Statue of Liberty green over 130 years.
The Aging Process
HOW COPPER TRANSFORMS OVER TIME
No other metal undergoes a more dramatic or beautiful transformation. Copper’s journey from salmon pink to vivid verdigris is a 100-year story told in color.
Fresh Cast
Pure copper's true color: a warm rose-salmon unlike any other metal — immediately recognizable
1–3 Years
Oxidation begins turning the surface to warm reddish-brown. The metal's character starts emerging.
5–15 Years
Rich chocolate and dark umber tones develop. The oxide layer seals the metal against further oxidation.
20–50 Years
The iconic blue-green verdigris of copper carbonate appears, first in recesses and corners.
50–100+ Years
The Statue of Liberty stage — a full, rich green patina that seals, protects, and defines the metal forever.
Full Specifications
Technical Data
Property
Value
Alloy Designation
C110 ETP (ASTM B187)
Composition
| 99.9% CU · 0.04% O · <0.1% Trace |
Casting Method
Sand casting, chemically-bonded mold
Pour Temperature
1,984°F (1,084°C)
Tensile Strength
32,000 PSI
Density
0.324 LB/IN³ (~8.96 G/CM³)
Standard Thickness
3/8 inch Base Field
Relief Height
| Up to 3/4 inch (Title Letters) |
Background Color
Hunter Green (RAL 6009), Baked Enamel
Clearcoat System
Marine-grade polyurethane, 25-yr rating
Mounting
Stainless 3/8″ anchor bolts (template incl.)
Outdoor Lifespan
100+ years documented
Warranty
Lifetime — full replacement
Note: The material specifications, alloy composition, and performance characteristics provided are for general reference only. Actual composition, mechanical properties, finishes, and aging behavior may vary based on manufacturing processes, environmental conditions, and application. Natural patina development and color changes in bronze will differ over time.
Why Choose Cooper
Seven Reasons COpper Wins
Most Dramatic Patina
No other metal undergoes a more stunning transformation. Copper’s journey from salmon-pink to vivid green verdigris is a living work of art that grows more valuable over time.
Deepest Historical Pedigree
Copper has been worked by human hands for 10,000 years. The Statue of Liberty, the Pantheon’s doors, ancient temple roofs — copper carries the weight of civilization itself.
Highest Intrinsic Value
At 99.9% purity, copper holds the highest commodity value per pound of any plaque material — a real-asset investment that transcends its commemorative function.
Self-Sealing Protection
Copper carbonate patina is not just beautiful — it is chemically hard and tightly bonded, creating a natural armor that actively protects the metal beneath.
Inherently Antimicrobial
Pure copper has well-documented antimicrobial properties. Copper ions actively suppress bacteria and viruses on the surface — a meaningful benefit for high-touch applications.
Exceptional Workability
C110’s purity and ductility allow for the finest detail reproduction in any casting alloy — portraits, fine script, and intricate borders come out razor-sharp.
