chartwell gallery

Quality Picture framing in Southend since 1977

A Glossary of Useful Framing Terms

Acid Pollution attacks cellulose fibers by shortening them, causing paper to disscolour, 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.

Disscolouration caused by acid migrating onto the artwork, often from the cut edge of the windowmount.

Containing no acid. Often used to describe board, paper or adhesive that has been treated to give a ph value of more than 7.

Acidity and Alkalinity are measured on a pH scale ranging from 1 to 14. The neutral point is 7.00 and at this point the substance or material is neither acidic or alkaline. The higher the number, the higher the alkalinity. The difference between numerals is significant because the scale is logarithmic which means each pH change of one indicates a change of 10 times the acidity or alkaline measurement. As a frame of reference, at pH 10 is soap; pH 3 is vinager. Conservation materials should be at pH 6.5-8.5. Paper can be naturally neutral or chemically neutralized. Although a paper may be acid-free or have a pH of between six and eight, it may become increasingly acidic over time.(extract from Conservation framing by Vivian Kistler)

The opposite to acidic. Alkaline materials are used in conservation framing and have a ph greater than 7. Calcium carbonate is commonly added to paper as an alkaline reserve, to counteract the paper's natural degradation. Alkaline reserves added to paper are often called buffers.

Includes techniques such as etching, lithography, woodblock printing and silk screening, created by and printed by the artist. BSI (British Standards Institution ) defines this type of print as a category 'A' where the artist creates the original work and makes impressions from the plate. If other people are involved in the printmaking process and not the artist, this defined by BSI as a category 'C' type print.

We use a solid white conservation board from Arqadia. Made from a high quality bleached alpha cellulose, the board is essentially lignin-free (see Acid entry ). Under accelerated ageing conditions the board changes from pH 9.4 unaged, to pH 7.5 over a 100 years; pH 7.5 in 150 years; pH 7.5 in 200 years.

We have been using Filmoplast P90 tape for about twenty years now to seal the glass/mount/foamboard package to keep out dust and insects. The tape is acid free, water based, and non-ageing.

Cibachromes are ultra high gloss photographs that are very sensitive to marking, and therefore demand the upmost care when handling. Cibachromes are produced by Iford, and are now branded as Ilfochromes. These photographs should not be drymounted, but hinged, for small prints, and placed onto acrylic sheet held by static force, for larger prints.

Drymounting is a method of sticking paper and light fabrics to a board without the application of wet glue. The drymounting tissue softens under heat and pressure in a vacuum press. We find this method very good for items of relative low value, such as posters and prints. Objects of value should never be glued to a board!

Digital prints from a image file that are produced from an printer using light resistant pigment inks that have greater luminosity than conventional lithographic prints.

A print made from an inscribed or etched plate. The copper plate is covered in wax into which the image is drawn. The plate is immesed into an acid bath which eats into the exposed parts of the plate. When the wax is removed the drawn image is etched into the plate allowing ink to fill into the design. The plate is put on an etching press and a roller then passes over the plate under pressure, picks up the ink image and rolls this onto a damp paper. Each colour is a separate proceess, and each print must be exactly aligned.

Approximately only 92% of light is transmitted through glass, the rest is reflected towards the viewer. Low reflection glass transmitts over 99% of light, giving a brighter, clearer image, with minimal reflection. Most types of Low-Reflection glass are coated with a multi-layer optical interference coating (OIC) which is very similar to the lens on cameras and binocolars. Coated glass must be handled and cleaned with care, as the coating can be vulnerable to scratching.

Light damage to artwork is the most pervasive and most difficult to avoid. Light will cause the paper and the artist's medium to change by fading, changing colour, altering chemicals in paper and paint, and degrading cellulose. The extent of the damage depends on the intensity of the light and length of exposure.

Artist Proofs are prints that tradionally have been used to check colour, and alignment, prior to the print run. Today artists' proofs are mostly a marketing tool and have no real intrinsic value. These prints are identified by the letters 'AP' usually in pencil on the bottom left margin of a limited edition.

We use Tru Vue Conservation Clear 2.5mm Glass which has a filter on the side facing the Artwork. This absorbs 98% of the damaging UV energy that exists just beyond the violet end of the visable spectrum. It is important to realize that UV Glass does not offer complete protection, and Artwork should still be shielded from direct and excessive sunlight. UV is defined as energy within the 300-400 nanometer range. Ultraviolet (UV) light transmits energy into the atoms of the object it strikes. This energy excites the atoms and transforms them into new substances, which manifests in artwork as fading and degradation of paper and fabrics.

This glass has very few flaws, and good optical properties, although it has a very slight greenish cast due to the iron content in its composition. Large works require 3mm Float Glass which is considerably heavier than the 2mm. We use this glass for items that do not require UV protection.

Silkscreen printing is a method of pushing ink or paint through a fine mesh that holds the stencil through which the paint passes onto the paper. Sometimes called Serigraphs, these prints are often printed in bold flat colours on heavy weight paper, normally in small editions.

 Watercolour paintings on paper should be hinged on to a conservation board, not stuck down. Often the paper is wavy in appearance but this is only the result of the water applied to the paper during the painting process and should be considered a natural consequence of the medium of watercolour. The technical term for this is cockling, and this is more pronounced on lighter rather than heavy weight paper. The artwork can be pressed flat before framing but this only reduces and does not eliminate the cockling. Watercolours are almost exclusively window mounted with a double mount often employed to give extra space between the glass and the artwork. A wash line mount may be used to further enhance the artwork. The mount is hand drawn with an ink pen and then a very thin watercolour wash is applied between the lines.

A strange phenomenon called photo-transference can occur on framed items under certain conditions when the glass lies directly on top of the artwork or print.  An image of the art is permanently transferred to the inside of the glass.  The image disappears when the glass is washed, only to return when it dries.  Photo-transference is caused by a chemical and light interaction with inks and  paints together with the gases in the glass.  The solution is to replace the glass and use a mount or spacer.

Sometimes fragile items such as newspaper articles and old documents need to be supported on the conservation board.  This encapsulation method, often used by museums, works by placing the item between two sheets of polyester film held together with double sided tape, with a small air space so the work can breathe. Letters and certificates are hinged on conservation board however when both sides are required to be shown the encapsulation method is used, the framing is sandwiched between two or more mounts and two sheets of glass, and then framed. Heavy items require a different method of support called a sink mount. A Magazine/Book or Artwork rests within a supporting cradle of foamboard to the required depth of the object, and a mount is fixed on top of the package, which in turn is glazed and framed.