Aubergine Etched Glass Amphora by Le Verre Francais

• Etched - Glass decorated with an etched design, which is achieved through marking out the pattern, protecting the area that is not be etched, and then immersing the object in acid to dissolve the surface of the unprotected area. With some glass objects, such as cameo glass, there may be several layers of different coloured glass, and part of the top layer is dissolved leaving the bottom layer as the background. The longer the time of exposure of the object to acid, the deeper the etching.
  
  The word etching is also sometimes used to describe another method of decoration, where wheel grinders were used decorate the surface, but this technique is usually known as engraving.
• Pontil Mark - A pontil mark, also known as a pontil scar, is a distinctive mark or scar found on the base of certain types of glass. It is a remnant of the glassblowing process and is particularly associated with handcrafted items made prior to the widespread use of automated manufacturing.
  
  The pontil mark is created during the final stages of production. After the glassblower has shaped and formed the glass object, it is removed from the blowing iron. At this point, the glass object is often attached to a solid rod called a pontil rod or punty for further shaping, finishing, or attaching additional components. The attachment point is typically at the base of the object.
  
  Once the glass item is complete, it is detached from the pontil rod, leaving behind a mark or scar on the base. This mark can take various forms, such as a rough or irregular surface, a concave or slightly recessed area, or a small circular scar. The presence of a pontil mark indicates that the item was handcrafted rather than mass-produced.
  
  Collectors and historians often use pontil marks as clues to determine the age, authenticity, and production methods of glass or ceramic pieces. Different types of pontil marks may suggest different techniques used in the production process. For example, an open pontil mark is one where the scar is left as an exposed, roughened area, while a closed pontil mark occurs when the scar is smoothed or covered in some way. It's important to note that not all handcrafted glass items have pontil marks, as some artisans developed alternative methods for finishing their work. In Edwardian times the pontil mark was oftern ground off leaving a concave circle in the centre of the base of the object.
  
  The use of pontil marks diminished with the advent of industrialization and automated manufacturing processes in the 19th and 20th centuries.
  
  

• Engraved Glass - The method of decorating glass by marking the surface with a sharp intrument such as a diamond, metal needle or rotating cutting wheel. As pressure is applied to the surface, best results for engraving are achieved if the glass is of sufficient thickness. In the 19th century etching was used to decorate some table glassware that was too fine to take an engraving tool.
• Acid Etched - Acid etching is often used on glass, metals, and stone to create decorative finishes or to prepare the surface for further treatment or coating. The process of acid etching involves applying an acidic solution, such as hydrochloric acid or nitric acid, to the surface of the material and allowing it to react with the surface. The acid etches away a thin layer of the material, creating a rough, uneven finish. Acid etching can be used to create a variety of different finishes, from a subtle matte finish to a more pronounced, textured finish.

This item has been included into following indexes:

• Schneider / Le Verre Francais (France)
  • glass makers 127
  • lamps and lighting 303