How to Authenticate Steuben Glass: Marks and Signatures
In its 118 years in business, Steuben was a leader in the luxury glass market. Both vintage and contemporary Steuben pieces are the frequent target of imitators, and forged marks and signatures are often applied to Steuben lookalikes. In this article, we’ll discuss some easy tests to authenticate genuine Steuben and how to detect fake and forged marks.
The Categories of Steuben Glass
Authentic Steuben can be roughly divided into two broad categories:
- colored glass from 1903–1932
- colorless crystal from 1933–2011
Although the marks of the two periods differed, the exceptional qualities of Steuben glass remained the same and are one of the best indicators of authentic Steuben.
Indicators for Authentic Steuben
1. No Mold Seams
Genuine production-run Steuben of both periods, for example, is never found with mold seams. All colored art glass, including lamp shades, was free-blown, never made in press molds. Some stemware from both periods was shaped with molds but never pattern-molded. Any piece purporting to be Steuben with obvious mold seams should be viewed with great suspicion.
2. Ground Pontils or Ground, Polished Bases
Almost without exception, genuine production-run Steuben of both periods has either a ground pontil or a base that is entirely ground and polished. Figural pieces made since 1933, for example, have perfectly smooth, ground, and polished bases. Art glass pieces such as vases have ground and polished pontils. The only exceptions to this general rule are certain stemware patterns of both periods with particularly high-domed bases.
3. Flawless Glass
The quality of the glass is virtually flawless. Clear crystal since 1933 virtually never has extraneous air bubbles in the glass unless bubbles are part of an intentional artistic design. Accidental dips, slumps, or burst bubbles are never present.
Glass color is consistent from piece to piece within sets of stemware, lamp shades, and other similar groups. Color may vary from set to set, but it's virtually always consistent from piece to piece within sets. Clear Steuben refracts only the natural prismatic rainbow of colors, never a single tint such as green—a sign of iron impurities.
4. Precise Construction
Construction of authentic Steuben is exacting and precise:
- Bowls are perfectly centered on stems of wine glasses.
- Vase bodies are centered on their bases.
- Hand-tooled surface decorations—such as pulled feathers, pinches, rim crimps, etc.—are of consistent appearance around the circumference or entire object.
- Applied glass objects (such as single handles on pitchers and cruets and double handles on opposite sides of vases) are perfectly centered and square to the glass bodies to which they are applied. They are also symmetrical from side to side.
- Sizes of matching pieces within sets are virtually identical.
- Fitter rims of sets of shades, diameters of stemware bases, heights of water tumblers, and other similar dimensions appear virtually identical in size.
5. Authentic Marks and Signatures
The marks are genuine and not forgeries. See below for detailed information on the different marks and signatures used by Steuben over the years.
List of Steuben Marks and Signatures
The only authentic standard mark on colorless Steuben made since 1933 is simply “Steuben” handwritten in ordinary cursive lettering with a diamond-tipped pencil (see above), producing very thin, slightly frosted lines. Regardless of the size of the piece of glass, the mark is quite small, generally about 3/16 of an inch high, about ¾ inches wide, and rarely over one inch long.
Forgeries of diamond-tip marks appear most frequently on inexpensive crystal made in Eastern Europe. Forged marks are generally quite large and appear on pieces with obvious mold seams.
Prior to 1932, Steuben used several marks that varied depending on the type of glass. Steuben’s line of iridescent glass, named Aurene, had “Aurene” or “Steuben Aurene” engraved on the base (see above), usually around the ground pontil. Authentic engraved marks may or may not include a catalog number.
Aurene marks were applied with a rotary engraving wheel and have a shaky appearance. No authentic Aurene mark was applied with a diamond-tipped pencil, vibrating engraver, or rubber-stamped acid.
Pre-1932 Art Glass
The majority of Steuben’s pre-1932 art glass was marked with an acid-stamped mark consisting of a fleur-de-lis with the word “Steuben” within a banner (see above, leftmost image). Genuine fleur-de-lis marks are quite small, only about 3/8 of an inch in height. The only genuine iridescent Steuben that is marked with the acid stamp is light shades. Acid marks on any other iridescent Steuben are forgeries.
A genuine fleur-de-lis mark also rarely appears as an acid cut back mark, the fleur-de-lis being raised above the surrounding surface. In those marks, the banner across the middle may read either “Steuben” or a specific line of Steuben such as “Calcite” (see above, rightmost image).
The most commonly forged Steuben mark is the acid-stamped fleur-de-lis. Almost all forgeries are way too large, frequently an inch or more tall. Many acid-stamped marks are badly blurred, almost illegible (see above). Original marks, even those with naturally occurring wear, have smooth, evenly formed letters that are legible despite being worn.