VOCABULARY TERMS: SURFACES

Surface. The outermost configuration of a solid or three-dimensional object, such as a numismatic or medallic item. Numismatics is the study of small surface area. The surface is everything – it carries the design, identifies the composition, provides the color and indicates the condition. The surface can be smooth, have detail, be textured, or can be treated – as with proof polishing – to indicate the intention of its designer. It can be colored, by enamel or patina. It can identify an anomaly should one have occurred in its manufacture. The surface is studied with a loupe or microscope to reveal its most discerning secrets. The surface reveals to those who can read it where and how it was made, as to whether it is genuine or false, expose its beauty or blemish, express its likeness or laxity. Enigmatic, revealing, captivating, informing, the surface of a coin or medal is the most important aspect of its existence.

Matte. A dull unburnished metallic finish without luster or sheen; an area of dead reflection. Matte surface, infrequently called mat surface, is produced by abrasive blasting with sand (or other grit abrasive), by matte dip (an acid that lightly etches the metal surface), or by matting tools (more often used in chasing). Matte finish is often used with proof surface for the contrast of reflectiveness – the main device is usually matte with the background or field in proof. Such dies are made by first masking the portion to have a proof surface, applying the matte dip to the area for the dead reflection, removing the masking material, then proof polishing the area to have the mirror surface. The contrast is quite startling. See reflectiveness, proof finish.

Matte finish on gold is called rose gold, this is not a color of gold, but a ruddy, matte finish of gold. It has no luster, but has the finish, it is said, of a rose petal.

Pebbled Surface. A background texture of raised dots or tiny hemispheres, each of which is called a BOSS. This form of texture can be made by modeling or by the use of the dapple tool in the negative model or in the die, or by a puncheon with an incuse cupped hemisphere. The Japanese developed this surface to a high degree for tsubas, they called this texture "fish roe surface" (nanako), where the bosses were as small as one-hundredth of an inch diameter. A pebbled surface is the opposite of dappled surface (where the dots are sunken indentations). See dapple tool, dapple surface.

Dappled Surface. A background texture of sunken dots or hemispheres. Such surface texture is made with repeated use of a dapple tool in the positive model or hub. It is the opposite of pebbled surface, raised dots or tiny hemispheres (which can be made with the same dapple tool in the negative model or die). The term for a single sunken indentation is a dapple; the term for a raised dot is a boss. A dappled surface is not considered an artistic texture (but more of a mechanical surface anyone can make).

Dead Reflection. A rough surface with virtually no reflective properties; matte surface. Rays of light are diffused and reflect off at all angles; opposite of mirror finish in which all rays are parallel from a very smooth surface. Dead reflection is created by abrasive blasting, or other matte producing techniques. See reflectiveness, matte.

Looking for the meaning of a numismatic word, or the description of a term?  Try the Newman Numismatic Portal's Numismatic Dictionary at: https://nnp.wustl.edu/library/dictionary

Or if you would like a printed copy of the complete Encyclopedia, it is available. There are 1,854 terms, on 678 pages, in The Encyclopedia of Coin and Medal Technology. Even running two a week would require more than 19 years to publish them all. If you would like an advance draft of this vital reference work it may be obtained from the author for your check of $50 sent postpaid. Dick Johnson, 139 Thompson Drive, Torrington, CT 06790.

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