Roux
Roux () is flour and fat cooked together and used to thicken sauces. Roux is typically made from equal parts of flour and fat by weight. The flour is added to the melted fat or oil on the stove top, blended until smooth, and cooked to the desired level of brownness. Butter, vegetable oils, bacon drippings or lard are commonly used fats. Roux is used as a thickening agent for gravy, sauces, soups and stews. It provides the base for a dish, and other ingredients are added after the roux is complete.
Royal Gold Cup
The enamel lies flush with the gold surfaces; it was a preparation of finely ground glass paste applied with great care to the prepared recessed areas, and then fired. Different colours of enamel meet each other with a neat boundary, which was achieved by firing one colour with a retaining border of gum tragacanth before adding the next. The difficulty was increased by the application of tints of a different colour to a base shade of enamel before firing, so that the added colour blends gradually into the background colour around the edges of the tinted area. This is especially used on "flux", or colourless enamel, as in the ground areas, rocks and trees. Flux was also used for flesh areas as on a gold background it darkens slightly when fired to a suitable colour for skin. The "rouge clair" or "ruby glass" red, used so effectively here, was made by adding tiny particles of copper, silver and gold to the glass; here scientific tests have shown that copper was used. After firing the enamel was polished flush with the surrounding metal. The technique had been known to the Ancient Romans (see the Lycurgus Cup, also in the British Museum), but was lost at the end of the Middle Ages until the 17th century. The added cylinders use opaque enamel, except for the red on the Tudor roses, which is translucent "rouge clair", of a similar composition to the original reds. Translucent enamel is more fragile than opaque, and medieval survivals in good condition are very rare.