Acetate: A fabric derived from either cotton or wood pulp that has undergone further processing thus classifying it as synthetic. It reacts badly to high heat and high concentrations of alkalis or acids. Acetate is an unusual base for fabric art.
Acid: acid attacks cellulose fibres by shortening them, causing paper to discolour, become brittle and eventually turn to dust. Exposure to light and damp accelerate this process. Acid is generated by the lignin (tree sap) in paper. It can also be introduced by chemicals used in paper manufacture, framing materials and atmospheric pollution.

Ballpoint needles: Needles with a blunt point. They stitch into the holes on cloth (eg canvas or aida) and do not pierce the surrounding threads. Also called tapestry needles.
Ballpoint pens: These should never be used for any framing project. Use only a pencil.

Calcium carbonate (chalk): This is the buffering agent most commonly used in the manufacture of paper. This alkaline reserve, usually about two per cent, reacts with pollutants and acid before they can attack the cellulose fibres, but it becomes used up and exhausted over time, ceasing to protect the paper.
Canvas: An open-mesh material which is generally the substrate for oil paintings and needlepoint, and is increasingly used for giclée prints. Canvas is produced in a variety of sizes and of varying fibres: cotton, acrylic, linen and plastic. Works on canvas must be stretched, or supported, over bars or board. Canvas slackens over time, so the artwork will eventually need to be re-stretched. (For the first 40 or so years oil paint is malleable and will yield as the canvas gradually slackens. Once the paint has dried, it may crack and flake as the canvas stretches).

De-acidification: De-acidification fluids can be bought which neutralise acid and apply a calcium carbonate buffer. Such fluids alter the composition of the paper and can affect colours, so it is not recommended that the framer use them.
Deckle edged: Paper with uneven, feathered edges, such as handmade paper. Deckle-edged paper is generally float-mounted with the edges showing.

Egg tempera: Water-based paint made from watercolour pigments that are ground with egg yolk. Used by the ancient Greeks and Romans but later supplanted by oil. See 'tempera'.
Emafyl: The brand name of a plastic moulding made in the UK. See 'plastic moulding'.

Fabric art: A generic term incorporating all art made mainly from fabric, including batik, cross stitch, embroidery, tapestry and woven materials.
Facsimile: Literally, an exact likeness, a copy replicating an original work. See also 'reproduction', the term used more generally in relation to contemporary fine art printing.

Gesso: Mixture of chalk and glue that forms the base of gilding. Gesso can also be carved, and can be used to decorate mounts and frames.
Giclée prints: Inkjet prints printed from a computer where the image has been stored as a digital file, and is then outputted onto paper or canvas with a high-resolution wide-format printer. The image may have been created on-screen or may have been scanned in to the computer. This relatively new printing technique is rapidly gaining market share.

Handmade paper: Paper made by hand using a mould, which is covered by a flat frame called a deckle, which in turn catches the run-off of wet pulp. The mould is dipped into a vat of wet pulp, shaken to distribute the fibres evenly and drained of excess water. The wet mat of fibres is then dried against blankets and may be hot pressed, cold pressed or air dried.
Hardwood: Wood from deciduous trees with broad leaves. Most hardwood is physically very hard, but not always.

Image size: The measurements of artwork that are to be visible within the frame and mount, including borders, if these are to show. Image size is not always obvious and can be a matter of taste, eg a customer may want a tiny image framed surrounded by a large expanse of paper. Sometimes referred to as window size, since it is the size to which the window aperture is to be cut.
Impasto: The textural 3D quality of paint. Paint applied thickly with a palette knife has a deep impasto. Impasto can be flattened by inexpert restoration.

Japanese paper: Used when framing to museum standards, particularly for making hand-torn hinges with which to support artwork. It is made from certain Far Eastern trees (eg Mulberry) and has long, strong fibres.

Kappa number: A test for the degree of lignification of pulps. Specifically, the number of millilitres of tenth-normal potassium permanganate solution consumed per gram of moisture-free pulp under standardised conditions.
Kent frame: Named after the 18th century architect and designer William Kent, this frame has square corners extending beyond the outer edge of the rest of the profile. Each corner is decorated with a flower; the centre is flat and outer edges are both decorated and raised.

Lacing: This is the traditional manner of stretching fabrics that are sufficiently strong. It is usual to stretch over suitable grade mountboard or foam board. The thread used for lacing should be of the same weight as the fabric or slightly lighter; if there is a problem, the lacing threads should break, not the fabric. The thread should be a continuous length that is pulled through with each stitch from side to side and then from top to bottom at even distances apart. Tension is achieved by pulling the continuous thread. This method is time consuming and therefore an expensive method of stretching, but is suitable for conservation work.
Laid papers: Papers with a grid pattern in the sheet, resulting from the pulp resting against raised wires on the papermaking mould screen. Laid lines are closely spaced while chain lines are further apart and run parallel with the grain direction of the sheet. The other main type of paper is wove (see below).

Masking tape: Cheap self-adhesive tape designed for temporary use. Not only is it acidic and therefore harmful, it will leave a residue which is impossible to remove. It is likely to fail more quickly than other tapes as it is not designed to stand the test of time. NOT suitable at any framing level.
Mat, matting, matboard: The US term for mountboard.

Needle art: Another term for embroidery, describing the decoration of fabric by needle and thread. There are hundreds of different stitches and types of embroidery and any type of fabric can be embroidered.
Needlepoint: Needlepoint describes any embroidery on canvas where the whole of the canvas is covered by stitching. The term includes gross point, quick point and petit point. Needlepoint often needs squaring before stretching because the diagonal stitch can distort the shape if over tensioned. The term ’tapestry’ is often erroneously used to describe needlepoint; tapestries are in fact woven, not sewn.

Oak: Hardwood used by framers wanting to hand-finish frames leaving the grain visible. The Victorians liked to finish oak in gold.
Obeche: A fine grained hardwood commonly used to make picture frame mouldings. Obeche is soft, has little character and is relatively cheap. It is ideal for painted finishes, though basecoats are needed as the surface is highly absorbent.

Padding: Polyester wadding can be used to pad fabrics. It helps to disguise knots and uneven tensions in fabric art and is particularly good behind silk embroideries, which are more difficult to stretch without rippling. It also provides a luxurious 3D appearance, although this is minimised when behind glass. Foam padding is not suitable because it degrades and discolours with age. (Also see ’knots’.)
Panel: Paintings on wooden panel can warp in extremes of temperature and may actually split. Restorers can remove the top layer of wood that holds the paint and lay this onto another panel.

Rabbet: US term for ‘rebate’, or the depth of the moulding.
Rabbit skin glue: Glue made from the skin of rabbits that is traditionally used in water gilding.

Safety glazing: Another term for anti-bandit glazing, meaning glazing that will not shatter if broken.
Samplers: Originally this term referred to a test piece of embroidery. However, by the 17th century, these practice pieces had taken a definite form and were known as samplers. Antique samplers are highly collectible and the value depends very much on the condition.

Tapestry: Commonly used term for ’needlepoint’, which is the correct term for hand-sewn designs of this type. Genuine tapestry is actually woven, not stitched.
Tapestry needles: The thickest type of needle available. They have a large eye, since most needlepoints are sewn in wool. They are available in a variety of sizes and are similar to chenille needles. Tapestry needles are blunt so that they do not pierce the threads or cloth. Sometimes called ballpoint needles.

Ultra-violet (UV) light: The invisible light at the violet end of the spectrum that causes paper to deteriorate and discolour, as well as fading some colour pigments. UV light is a major threat to the longevity of works on paper.
Unbuffered: Board or paper that has not been treated with an alkaline reserve. See ’buffered’.

Velcro: An ingenious fabric incorporating two compatible strips, one covered with tiny hooks the other with loops. The two when pressed together provide a strong and tight bond. Two types are available: self-adhesive and plain for stitching. Velcro can be used to support large unwieldy textiles. A frame can be made, the velcro attached to the frame and rear of textile, and the two can be stuck together but removed if necessary.
Vellum: Fine parchment made from burnished calf, kid or lamb skin. Vellum tends to be harder than other parchments.

Warp and weft: These names refer to the construction of fabric and some paper. Woven fabrics are produced from interlocking fibres at right angles to each other. The warp runs from top to bottom and the weft runs from side to side. Imagine an old weaving loom: the warp threads are attached to the front and back of the machine. The weft produces the selvage edges. (Weft = west-east.)
Washline: A decorative line drawn around a window aperture, traditionally using a special ruling pen and watercolour paint.

Xylography: The art of engraving on wood; the term therefore covers both wood engraving and woodcut printmaking techniques.

Zeolite: Zeolites are chemical components that can be incorporated into mountboard to form molecular traps which help protect the board from becoming acidic due to atmospheric pollutants.

A full glossary is available in The Directory 2006/07. Please call Moira on 020 7381 6616 to order your copy NOW!