| Absorbent Paper: |
a paper used to make casts of mosaics, when soaked with water it becomes plastic and sticks to mosaic surfaces perfectly |
| Air-Setting Mortar: |
a mixture of water, aggregate and a non-hydraulic binder that sets in air but is dissolved by water such as lime or gypsum plaster |
| Andamento: |
the direction of the rows of tesserae; horizontal, circular, or sinuous lines |
| Aventurine: |
type of glass paste containing sparkling gold colored particles exclusively employed as wall decoration |
| Background: |
the area surrounding a figure |
| Bedding Mortar: |
a layer of mortar which makes up the foundation of a mural or floor mosaic |
| Binder: |
a substance used to bind particles together, ensuring consistency and solidification; the process of setting can be through the loss or absorption of moisture or by a chemical reaction |
| Burnt Lime: |
a caustic substance that is prepared by burning calcium carbonate limestone at approximately 900 degrees Celsius; at this high temperatures carbon dioxide is driven off and the limestone is converted to quick lime |
| Cartoon: |
the full-size drawing on which the final mosaic is based |
| Cement Mortar: |
a mixture of approximately three parts sand to one part Portland cement with water |
| Chip Mosaic: |
mosaic formed from irregular chippings of stone |
| Chopping Machine: |
used for cutting stone and smalti into tesserae; it has two blades, the bottom one being fixed while the top one is moved by a wheel so that it falls exactly over the fixed blade |
| Flat Headed Nails: |
used to help plaster bind to a wall; strong nails with large flat heads |
| Intarsia: |
decorative technique in wood or stone in which pieces of different color and equal thickness are cut to the shape according to the design and then attached to a support; also called inlay |
| Interstice: |
the space between each tessera that is filled with grout |
| Mortar: |
a mixture of binder, aggregate and water that will set hard over a period of time |
| Pouncing: |
a technique used to transfer the design on a cartoon directly to the work surface; the design is pricked through along the contours and then pounced with charcoal dust so that the design is left on the surface underneath |
| Pigment: |
a substance added to the glass paste or limestone to give it color |
| Rainbow Style: |
style of mosaic where the colors of tesserae are arranged in diagonal sequence instead of rows |
| Rotino: |
a small grinding wheel turned by hand used for shaping tesserae so that each join together perfectly |
| Statumen: |
layer of rubble underneath the mortar bedding for a mosaic pavement |
| Tessera: |
the basic unit of mosaic; a small piece of glass or stone, or any other material suitable for mosaic work, cut to a square, rectangular, triangular or other regular shape |
| Tessellatum: |
commonly used in the phrase opus tessellatum to distinguish floor mosaic from wall mosaic |
| Underpainting: |
a fresco painting on the top plaster coat when the mortar is still damp |
| Vermiculatum: |
literally ‘worm like’; commonly used to describe the technique of pictorial mosaics made with minute tesserae |
