Sinclaire: American Brilliant Cut Glass from Corning, New York
H.P. Sinclaire & Company operated in Corning, New York, from 1904 to 1929, producing some of the finest American Brilliant Period cut glass and later transitioning to elegant engraved crystal. Founded by Henry Purdon Sinclaire Jr., a former Corning Glass Works and T.G. Hawkes employee, the firm earned a reputation for exceptionally deep, precise cutting and sophisticated engraved designs that rivaled any American glasshouse of the era.
Identification & Marks
Sinclaire glass is identified by an acid-etched signature, typically "Sinclaire" in script within a wreath-like border, or occasionally block-lettered "S" marks on earlier pieces. Not all pieces were signed; the company sometimes left blanks unmarked, particularly smaller items. Sinclaire purchased high-quality blanks from Corning Glass Works, Dorflinger, and European suppliers, then cut or engraved them in-house. The quality of the lead crystal blanks used is notably heavy and produces a clear bell tone when tapped.
Types & Styles
Brilliant Cut Glass (1904-1915): Deep, geometric cutting patterns including pinwheels, hobstars, fans, and strawberry diamond motifs. Pieces include punch bowls, compotes, decanters, and large presentation vases. Engraved Glass (1910-1929): As tastes shifted, Sinclaire excelled at copper-wheel engraving featuring flowers, fruits, and Adam-style neoclassical borders. Engraved pieces on colored glass (green, amber, blue) are especially rare. Art Deco Period: Late production included streamlined shapes with restrained engraving, reflecting 1920s modernism.
Auction Price Ranges
| Item | Price Range |
|---|---|
| Brilliant cut bowl (8-10 inch, signed) | $300-$1,200 |
| Large brilliant cut punch bowl on stand | $1,500-$6,000 |
| Engraved vase (clear, signed) | $200-$800 |
| Engraved colored glass vase or bowl | $500-$2,500 |
| Cut glass decanter with stopper | $250-$900 |
| Presentation or exhibition piece | $2,000-$10,000+ |
| Small signed dish or nappy | $100-$350 |
Condition Factors
Chips to the rim or cutting points are the most common damage and significantly reduce value, often by 50% or more. Check the feet and bases of bowls for fleabites. Cloudiness or lime deposits inside decanters lower desirability. Original stoppers matched to decanters are essential for full value. Engraved pieces should show sharp, unfaded designs; worn engraving suggests excessive use or polishing. Signatures should be clear and legible; pieces with confirmed Sinclaire signatures command a 30-50% premium over unsigned examples of comparable quality.
Collecting Tips
Sinclaire glass is undervalued relative to Hawkes and Libbey, making it an excellent entry point for American Brilliant cut glass collectors. Focus on signed pieces when possible, as they hold value more reliably. Engraved colored glass from Sinclaire is genuinely rare and worth pursuing at auction. Learn to distinguish Sinclaire's characteristically precise cutting style from competitors. Handle all cut glass by the base, never the rim. Display away from direct sunlight to prevent shelf burn on colored examples. The Corning Museum of Glass holds reference examples for study.