Silverprint Ltd, Choice of paper.

Choice in traditional papers

Base Types

Fibre-Based papers use a very highly refined woodpulp base. Such papers have no plastic coating, and consequently absorb all processing solutions into their core. Because of the problems this presents, careful processing and thorough washing is necessary if the print is to be preserved in good condition. For archival permanence fibre-based prints should be air-dried, but since they may not dry flat by this method they may require flattening under weight or in a dry-mounting press. The look and feel of well crafted fibre-base prints communicates quality and excellence, and these papers are well suited for exhibition purposes. If archivally processed, washed, and dried, then properly stored, they offer a standard of permanence not yet assured of resin-coated prints.

Resin-Coated papers are a modern convenience material. A thin plastic layer on each side of the paper base prevents chemical penetration, reducing washing time enormously. Prints drip-dry flat. Useful where speed is of the essence, and possible compromise of image quality and guarantee of permanence is acceptable.

Weight

The base thickness can be double weight (240 grams / sq.metre) or single weight (140 gsm), and some papers are now using 300gsm museum or premium weight. Most fibre papers are now only in double or premium weight, as this is the easiest to handle, and dries reasonably flat. Thin weights are available in some document papers, useful for collage/photo-composite work as they paste-up very flat. RC papers usually come in a standard medium weight., although a premium weight version of Ilford Multigrade 1V is available, called Portfolio.

Emulsion

Variations in sensitivity and final image colour result from the relative proportions of the sensitive silver salts used. The general pattern is that the higher the silver chloride content the warmer and slower the paper and conversely, the higher the silver bromide content the cooler and faster the paper. However, whilst this remains generally true, advances in computer modelling of crystal structure have meant that materials such as Agfa Classic and the new Ilford warm variable contrast paper achieve warmth largely through crystal manipulation rather than increased proportion of chloride. This has made possible fast, flexible, variable contrast warm papers that, understandably, do not retain all of the traditional chloride attributes- in particular toning characteristics are typically more akin to cooler emulsions.

Chloro-Bromide Papers

These traditionally have emulsions biased to an excess of silver chloride, eg 40% silver bromide, 60% silver chloride. This gives characteristically warm tones, (i.e. with a yellow/brown bias). The degree of warmth can be controlled to some extent by the selection of developer- choice from the cold, neutral and warm working developers in the Tetenal and Agfa ranges are useful in exploring this. The chloro-bromide papers are influenced considerably by toners, the most popular treatment being with selenium toner. This group of papers includes Kentmere Kentona and Art Classic, and Forte's Polywarmtone VC and Fortezo Museum.

Bromo-Chloride Papers

Not a term in common usage, but including most of the more 'neutral' tone papers used. Typically silver chloride content may be 40%, silver bromide content 60%. Colour variations with different developers are less marked than with chloro-bromide types, and selenium toning is likely to be to a more pure purple colour. Papers coming into this category include Ilford Galerie, and Oriental 'Seagull'.

Bromide Papers

High bromide content, tending to give a very cold, blue-black image. Forte Bromofort and Polygrade are the notable papers here.

Surface

Glossy paper renders the deepest blacks, and should be the choice when trying to present the widest tonal range. Matt paper has a somewhat reduced tonal range, since diffuse reflection from the surface reduces the depth of the maximum black. However many regard matt papers as having a superior tactile quality, giving the photographic print affinity with art-work in other media. Matt surfaces are likely to be most suitable for hand colouring and other manipulations. At one time there were many variations of texture between these two extremes, but for fibre-based paper the only common options now are variations on lustre or stipple. These have a coarse texture, and one attribute is that negative grain tends to get lost in the corrugations of the surface. Practically all stipple papers on the market have a matt finish, including the textured matt Kodak Ektalure, Agfa Classic 118 and Kentmere Fine Lustre. A few papers have a very rough surface, mainly from Kentmere, their 'Art' papers have a slightly rough texture akin to a 'Not' surface watercolour paper. Semi-matt papers are a useful alternative, available in Forte Polywarmtone and the new Multigrade FB Warmtone from Ilford.

Contrast Grade

Fixed graded papers come in numbered grades; a low number means the paper will print to low contrast (soft). A high number means high contrast (hard), indicating the paper will print to a high contrast from a normal negative. The grade of paper is chosen to match to the negative giving the contrast required in the print. A thin, possibly under-developed negative is likely to need a hard grade of paper to produce correct print contrast, while a negative with a high contrast range, possibly over-developed, will need selection of a low grade. A negative processed according to the manufacturers instructions, of a normal subject, should fit onto a grade 2 or 3. The degree of contrast in relation to grade number is NOT absolutely constant from one manufacturer to another. If in doubt which grade to select, go for the harder one. Bear in mind that although you cannot increase paper contrast to any great extent, it is possible to reduce paper contrast significantly, using techniques such as 'flashing' (controlled fogging exposure to white light) and the use of soft-working developer such as Agfa Adaptol.

Multigrade or variable contrast (VC) papers carry no grade number, and contrast is controlled by selection of a mix of yellow and magenta filters in the path of the enlarger light source. The paper carries two emulsions, one of low contrast and preferentially sensitive to yellow light, and the other high contrast emulsion responding preferentially to magenta. The Multigrade system as originally defined by Ilford now dominates the market, and virtually all manufacturers offer VC options. The advantages are considerable; use of it obviates having to keep a choice of grades through a range of sizes, and the facility of varying grade as a printing control is a valuable advance. However this switch to VC is killing older graded paper ranges by degrees, and in a few years to come it is likely that the only 'graded' varieties will be specialised types that cannot be replaced by VC emulsions. The type of enlarger light source itself will also substantially affect the contrast of the print, with a condenser head giving a contrasty print, a cold cathode giving a softer one, and the many varieties of tungsten mixing-box heads giving something in between.

Size

Papers come in a range of cut sizes from postcard up to 20x24", or rolls of widths up to about 50". The sizes are traditional, some based on sizes of glass plates used in early photography- hence widespread use of inches, and curious fractions when in metric.

Storage Life

Being much slower than films, most papers can be kept for several years in reasonably cool and dry conditions. The outside limit, for example, on Record-Rapid paper, before unacceptable changes occur has been put at 5 years. If there is a need for very long term storage, paper will keep almost indefinitely when deep frozen. Packs should be thoroughly sealed against moisture.