Missing Cladding (MCL)
A Missing Cladding error occurs on clad coins when one or both of the outer cladding layers fail to bond to the copper core and separate before or after the strike. The result is a coin that displays the copper core's reddish-brown color on one or both faces instead of the normal silver-toned copper-nickel surface. Missing cladding errors are visually striking and immediately recognizable.
How Does It Happen?
U.S. dimes and quarters have been struck on clad planchets since 1965: two outer layers of 75% copper / 25% nickel bonded to a pure copper core. Half dollars followed in 1971 (from 1965 to 1970 they were a different, 40% silver clad), and so did the Eisenhower dollar for circulation (1971-1978) and the Susan B. Anthony dollar. The three-layer strip is made in stages:
- Core and cladding strip: Copper strip for the core and much thinner copper-nickel strip for the two outer layers are prepared separately.
- Bonding: The three strips -- cladding, core, cladding -- are fed together into a bonding mill, which presses them into a single composite strip.
- Rolling: The bonded three-layer strip is rolled to the final thickness required for the denomination.
- Blanking: Round blanks are punched from the bonded strip.
Missing cladding errors occur when the bond fails or a layer is absent. Error-Ref describes several routes:
- Poor bonding: Part or all of a clad layer never fuses with the core in the bonding mill. Error-Ref suggests the strips may not have been cleaned well enough before bonding. When the poorly bonded layer falls away after blanking, the planchet arrives at the press with one face of bare copper.
- A layer missing from the strip itself: If one clad strip enters the bonding mill late, ends early, or has a gap, that part of the composite strip has only two layers and is still rolled to full thickness. Blanks from it can weigh the same as a normal coin. Error-Ref calls this a very rare rolling mill error.
- Separation after the strike: A weakly bonded layer can split away after the coin is struck. The exposed copper then shows the design, but Error-Ref describes the exposed design elements as characteristically mushy. The detached layer, struck on its outer face, can survive as an error of its own.
How to Identify a Missing Cladding Error
Missing cladding coins have unmistakable characteristics:
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Copper color on one or both faces: The most obvious feature. Instead of the normal silver-gray appearance, the affected side shows a warm reddish-brown copper color. This is the exposed pure copper core.
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Normal appearance on the intact side: If only one cladding layer is missing, the other face looks normal -- silver-toned with full design detail. The contrast between the two sides is dramatic.
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Reduced weight, in most cases: A coin whose clad layer was lost before the strike weighs less than a normal example. Error-Ref gives a single dime clad layer as about 0.4 grams and says a quarter missing a layer before the strike should weigh about a full gram light. For reference:
- Normal Roosevelt dime: 2.268 grams; missing one clad layer: roughly 1.9 grams
- Normal Washington quarter: 5.670 grams; missing one clad layer: roughly 4.7 grams
- Normal Kennedy half dollar (1971 on): 11.340 grams; missing one clad layer: roughly 9.4 grams
The exception is the coin struck on a section of strip that never had the layer: it can weigh the full amount.
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Copper visible on the edge: On a normal clad coin, the edge shows the three-layer sandwich -- copper-nickel on top and bottom with a copper stripe in the center. On a coin missing one cladding layer, the copper on the edge reaches all the way to the affected face.
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Thinner on one side: Hold the coin at eye level and examine its profile. A coin missing a layer before the strike is thinner than normal.
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Weaker design on the copper side: The design on the missing-cladding side is often slightly weaker or less detailed than normal.
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Copper underneath, not copper-nickel: A lamination can peel away part of a clad layer's surface, but Error-Ref points out that in a lamination the copper core is not exposed. If the metal underneath is copper-nickel colored, the coin has a lamination, not missing cladding.
Missing Cladding vs. Plated or Altered Coins
Normal coins can be plated with copper, or have their cladding chemically stripped, to simulate this error. Authentication points:
| Feature | Genuine Missing Cladding | Altered Coin |
|---|---|---|
| Weight | Usually below normal | Normal weight (if plated) or below normal but with chemical etching marks |
| Edge | Asymmetric -- copper extends to one surface | Normal three-layer edge (if plated) or chemically attacked edge |
| Surface texture | Smooth, struck copper surface | Plating bubbles, brush marks, or chemical pitting |
| Design detail | Slightly weak but normally struck | Normal detail (if plated) or degraded from chemical stripping |
Notable Examples
Roosevelt Dime Missing Obverse Cladding
A Roosevelt dime showing Roosevelt's portrait in copper with a normal copper-nickel reverse is a classic example of this error type. Error-Ref also illustrates a separated dime clad layer on its own.
Bicentennial Quarter Missing Reverse Cladding (1976)
The 1976 Bicentennial quarter carries Jack L. Ahr's Colonial drummer reverse. Error-Ref shows a 1976 quarter struck on a planchet cut from strip that lacked a clad layer from the start: at 5.39 grams it is just 0.28 grams light, because the blank came from a tapered end of the strip.
State Quarter Missing Cladding
The 50 State Quarters Program (1999-2008) produced missing cladding errors across the series. Error-Ref illustrates a 1999-P Georgia quarter struck on a planchet missing part of its obverse clad layer.
Coins Missing Both Clad Layers
A blank can also lose both clad layers, or be punched from an edge of the strip where the copper core extends beyond the cladding. Error-Ref shows an undated copper core piece that was fed into the press with a normal quarter planchet, stuck to the reverse die and was struck repeatedly until it spread to about the diameter of a half dollar.
The Mint's riddlers are mechanical sifters that remove undersize, oversize and misshapen planchets and coins. They sort by size and shape, not weight, so a blank of the right diameter that is light or thin is not what they are built to catch.
Pre-1965 Silver Cladding Distinction
Missing cladding errors apply only to clad coins. Pre-1965 dimes, quarters and halves were struck in a homogeneous 90% silver alloy with no cladding layers, so a discolored pre-1965 silver coin is not a missing cladding error; it is toning. The 1965-1970 half dollars and the silver Eisenhower dollars sold to collectors were clad, but with silver alloy layers rather than copper-nickel.
Collecting Tips
- Weight is the first test: Before buying a suspected missing cladding coin, weigh it. Most genuine examples are clearly lighter than normal. A coin of full weight needs a closer look: it may be plated or toned, or, less often, a genuine coin struck on strip that never had the layer.
- One side missing is more common than both: Coins missing cladding on one side represent the large majority of examples.
- Check the edge and the color underneath: Copper reaching one face on the edge, and copper rather than copper-nickel under any peeled area, separate a missing clad layer from plating, toning and laminations.
- Authentication is important: Given the ease of faking this error through plating or chemical alteration, certification by PCGS or NGC is worth having.
- Look for combination errors: Missing cladding sometimes occurs alongside other errors -- particularly laminations, clipped planchets, or off-center strikes.
- Condition still matters: Original copper luster on the exposed face is easier to evaluate than a circulated, darkened surface.