Kitchen utensil the turn of the 20th century, Maria Parloa noted that kitchen utensils were made of (tinned or enamelled) iron and steel, copper, nickel, silver, tin, clay, earthenware, and aluminium. The latter, aluminium, became a popular material for kitchen utensils in the 20th century. Copper has good thermal conductivity and copper utensils are both durable and attractive in appearance. However, they are also comparatively heavier than utensils made of other materials, require scrupulous cleaning to remove poisonous tarnish compounds, and are not suitable for acidic foods. Copper pots are lined with tin to prevent discoloration or altering the taste of food.
Cold foil printing transfer. The best results are obtained on glossy coated papers and papers with a smooth surface. Weights from about 80 to 500 g/m^2 are possible. The process does not require stamping tools, but instead uses printing plates, which are cheaper and can be made in a few hours. In contrast, delivery time for an engraved or etched stamping tool can be up to two weeks. More importantly for the designer, gradients and halftone images can be introduced. Cold foil evolved from hot foil stamping. Hot foil stamping is mostly used offline when foil is required on a preprinted substrate, such