Bole – A clay layer applied directly beneath a layer of water gilding that allows gold leaf (for example) to be burnished to a high polish. Frequently, burnished area can be seen as shiny highlights on a gilded frame or mirror.

Cultural Property - Objects, collections, specimens, structures, or sites identified as having artistic, historic, scientific, religious, or social significance.

Consolidation – To add an adhesive, or incorporate a material, that solidifies or stabilizes a structure or material.

Cradling / Painting Cradle - Wooden battens (cradles) are sometimes added to the back of a wooden panel painting in order to keep the panel painting, or its individual wooden planks, that comprise the panel, flat or in plane. Battens allow the panel to expand and contract with changes in temperature and humidity without causing damage. The first set of glued-on battens (2-3” apart following the grain), have a series of rectangular cut-outs for the second set of battens to slide through creating a grid. This is an extreme, but usually effective, means of repair for a severely damaged panel painting, and should only be attempted by a professional conservator with vast experience in the restoration of panel paintings.

Inpainting – When a conservator uses paint to replace missing paint on an artifact, re-paints filled areas, or thinly applies paint to abraded sections of a painting or painted surface. The reason that it is called “inpainting,” is because the conservator is only repainting or painting-in the areas or brush strokes that are missing, and not repainting or retouching (as it used to be called) an entire section, color panel or background to cover up the damage.

Facing - The addition of a temporary layer of tissue paper, gauze, or long fibered synthetic paper attached with a removable adhesive to the front of a painting, or mural, to secure the original paint while handling the artwork. A “facing” is used solely as a protective layer to temporarily safeguard the original paint during a necessary step or process in treatment, or during transport that we need to do.

Frame Fillet or Liner – A fillet is a thin gilded, stained, or painted wooden strip that is added to the inner edge of a frame, that allows you to expand the dimensions of a frame so that the painting or print does not fall through the opening. A frame liner is about the same thing, but is larger. Frames frequently are made to be wider or grander by adding additional frame molding pieces on the inside of a frame. A liner basically acts as a wooden window mat for a painting, or work-of-art on paper.

Gilding – Application of an extremely thin sheet of aluminum, gold, silver or metallic leaf to an artifact or frame.

Impasto – A thick heavy 3-dimensional paint layer.

Interstices – A small space or crack between two things. Generally, this is a word used in conservation to describe lower/deeper troughs of a paint layer, particularly if the paint stroke was applied very thickly.

Lining – The addition of a secondary support canvas, panel or backing to a painting to help support an original canvas that is very fragile, has large mended tears, or can’t support its’ own weight.

Medium – The binder or adhesive used to hold paint together (ex. oil paint, water color, egg-tempera, gouache, acrylic).

Overpaint - A term conservators use to denote when a restorer heavy-handedly repaints a section, tear, loss, or abrasion on a painting extending their repair (retouching) well past the boundary, or extent of the actual loss.

Plain Weave Canvas- The threads in this type of woven fabric all run in a simple perpendicular weaving pattern that resembles a simple checkerboard pattern.

Preventive Care (also referred to as preventive conservation) - The slowing down or stopping of deterioration and damage to cultural property through the establishment and implementation of policies and procedures for the following: appropriate environmental conditions; handling and maintenance procedures for storage, exhibition, packing, transport, and use; integrated pest management; emergency preparedness and response; and reformatting/duplication.

Primed Canvas - The process of creating a barrier between the canvas and the paint of a painting. Typically this is done by applying layers of acrylic gesso, clear acrylic medium, traditional hide glue, or oil paint primer.

Rabbet – This is a French word, which refers to the inner lip of a frame that covers the outer edges of a painting.

Selvage Edge - An edge produced on woven fabric during manufacture that prevents it from unravelling.

Tacking Iron - A small hand-held electric wand-like implement that has a metal surface that can be temperature regulated. This allows a conservator to apply heat to a small area of an artifact in order to melt/activate an adhesive, flatten paint, or to relax and reattach lifting wooden veneers from a frame.

Twill Weave Canvas - The threads of a twill weave canvas run in a ribbed diagonal pattern, while a normal canvas/fabric is woven in a “plain or basket weave.”

Strainer/Stretcher – A strainer is a fixed corner wooden framework that a painting is mounted to, or stretched over. A stretcher is not joined in the corners, but has wooden triangular flat wedges (1 or 2) in each corner that when tapped lightly with a hammer allows you to expand the stretcher slowly, and therefore the painting.

Stretcher Key - Wooden triangular flat wedges (1 or 2) in each inner corner of a wooden stretcher that when tapped lightly with a hammer allows you to expand the stretcher slowly and therefore the painting, which becomes more taught or in-plane. To key-out a painting means to make it more taught on its stretcher.

Underdrawing - Sketched lines made by a painter as a preliminary guide, and subsequently covered with layers of paint. Infrared irradiation of the painting’s surface allows conservators to document these normally unseen sketches.

Vacuum Hot Table – A large table that a conservator uses to line a painting, consolidate flaking paint on a painting using an adhesive, or to humidify and relax flaking paint or a distorted canvas. This table generally has a continuous sheet of aluminum on top with heat coils or sheets below. The table is heated to melt adhesives or waxes into the structure of a painting to consolidate flaking paint layers. The table also has a vacuum pump or system that allows the conservator to pump out air between a clear covering sheet and the painting. When the table is heated and the vacuum is turned on, the paint layers will relax and flatten. When the heat is finally turned off, the artwork will cool under vacuum allowing it to remain flat or back into its original configuration.

Wet into Wet Painting - The wet-on-wet technique in oil painting, also known as 'alla prima' is where you apply a new layer of oil paint, on top of a still-wet layer rather than waiting for a layer to dry before applying the next. Conservators frequently use this term when describing whether an artist signed a painting when the composition was still wet, or afterwards when dry. If it was then there is a chance that the signature was not added by the artist, and could be a signed forgery.

Conservation Terms