Like most materials, glass expands when heated and contracts on cooling. When hot glass is cooled quickly, the surface sets and suddenly contracts while the item's core, which is still at a very high temperature, carries on expanding. This results in very high tension which can eventually lead to the item's breakage or spontaneous explosion. Annealing helps to eliminate this tension. The operation consists of first heating the item to about 500°C and then cooling it very slowly, so as to maintain an even temperature.

Arches are furnace chambers used to anneal glass items.

The base is the name given to the bottom part of a stemmed glass.

Borosilicates give cookware (casseroles, oven dishes etc.) specific properties such as:
- resistance to thermal shock,
- easy cleaning due to a special surface treatment,
- compatibility with both traditional and microwave ovens,
- hygiene due to their totally smooth surface that prevents the build up of food residues,
- transparency, making it easy to monitor food as it cooks.
Borosilicates are also used in a pharmaceutical context to make neutral glass, in the lighting industry, for the windows of washing machines and certain other very specific uses (coffee pots, coffee makers etc.).

This refers to the initial shape given to the glass by blowing. The bowl is the part of the glass (with or without a stem) that contains the liquid.

Casing is a technique that dates back to ancient times and which consists of placing layers of glass on top of each other, one of which is coloured.

Crystal results from the fusion at about 1,500°C of three main components: sand, potassium hydroxide or soda and lime, as in the making of glass, but with an extra element that gives it its special qualities: lead. Mixed with sand, lead gives crystal its sparkle and resonance. To be called crystal, glass must contain at least 24% lead oxide. There is also crystal that contains 32% lead oxide, but this is rarely produced now because of its excessive fragility.

Cullet

Glass is a recyclable material. Glass to be recycled is broken up (= cullet) and mixed with the other components to supply the furnace.

Engraving is a decorative technique carried out using a wheel, acid or a pantograph.

Feeders are the channels that transport molten glass from the furnace to the machines..

This is an opaque glass used exclusively for household items: plates, bowls, etc. This material offers several benefits:
- 100% recyclable,
- non-porous for absolute hygiene,
- very good resistance to mechanical shock (two to three times greater than traditional crockery), thermal shock and scratches,
- lighter than porcelain,
- dishwasher-safe.

Flux is a basic oxide (soda, potassium, lime, lead oxide) which helps to melt silica during the fusion of the glass.

The foot of a stemmed glass refers to the stem and the base.

Frosting is a process that gives a material a matt finish. It is achieved by sand-blasting or acid, or a grinding wheel.

Furnaces enable the fusion of glass.

Fusion is a crucial stage in the glass making process as it transforms the mixture of raw materials into a homogeneous paste at 1,500°C.

First stage in cutting.

K_______________________

Kwarx®

Kwarx® was developed by Arc International's research centre and brings together the best qualities of existing glass-making materials; it is extremely pure.
• Kwarx® has incredible resistance to mechanical and thermal shock.
• The glass's absolute transparency allows the full chromatic range of wines to be expressed.
• Kwarx® keeps its amazing shine wash after wash.

The lip or rim is the name given to the part of the glass where you place your lips.

Polishing involves buffing and removing any final imperfections by dipping the item in an acid bath or rubbing it with soft materials.

First cutting operation.

Silica accounts for a large proportion (60 to 75 %) of the composition of glass. It can take the form of sand, sandstone, pebbles or quartz.

Sodalime glass is used to produce articles such as stemmed glasses, vases, cups, salad bowls, as well as decanters, jars and jugs. It is also used in the building sector for glazing and in the automobile industry for windscreens, headlights etc.

The stem is the part of the glass that joins the base to the bowl.

Tempering is a technique that consists of reheating glass evenly (to about 500°C) so that it expands, and then cooling it rapidly by blowing air on all of its surfaces. This considerably increases the glass's resistance to mechanical shock (by up to a factor of five) and also its resistance to sudden changes in temperature (delta T 130°C); if the glass does break then tempering makes it less dangerous because the shards are very small and not sharp.

Non-porous, vitroceramic glass is completely safe and hygienic. It holds heat very well and is able to withstand differences in temperature, easily moving from hot to cold and vice-versa. These properties make vitroceramic products suitable for all types of cooking (except induction): gas, halogen or electric hot plates, traditional and microwave ovens.