To allow a photograph to show its true beauty, it has to be displayed properly. As an analogue or digital print, with or without frame. But what paper is best to use and why? How durable is photo paper, what do collectors or museums want and what does a photographer want? GUP offers you a short guide to printing.
Dark Room Printing
Printing by hand in the dark room provides optimal certainty in terms of durability; the processes are relatively well tested. If you use the correct materials, development times and exposure times, the result will be a print of high quality. Extensive instructions are available for developing, rinsing and fixation. Not only provided by suppliers, but also by museums as they regularly advise photographers on how to make a specific print. Important is that the various baths have exactly the correct composition, according to the factory specifications. The temperature must be maintained at a constant temperature, to benefit preservation. The baths must be changed regularly. Once the print is ready to dry, avoid running it through a shining device to give the print a glossy finish. The gloss can contain chemicals that will continue to affect the print, creating spots over the years. It is better to dry them horizontally, with bulging as a minor side effect.
The best prints from the dark room are Gelatine Silver prints. Provided they are well developed and dried, these prints have the longest durability. Almost all types of photo paper for black-and-white prints have an optical whitener - barite - that makes the whitest parts appear even whiter. Barite has no effect on durability, only on the whiteness of the paper as it turns slightly yellow over the years. Then there is Resin Coated (RC) paper, with a synthetic resin finish called polyethylene. RC prints are available for both colour and black-and-white. In the past, black-and-white RC paper was ideal for photojournalist who had to race to the darkroom to get the prints to the editors as quickly as possible. As a synthetic medium, Resin Coated paper dries extremely quickly. Unfortunately, black-and- white RC prints are a collector’s nightmare. The prints cannot be framed, unless they have been finished with selenium or gold toning, which very few actually have. Thankfully, colour RC prints cause no problems. Most of the modern colour prints are chromogenous prints or Type C prints. They should not be exposed to light too long so exhibition periods must be alternated with periods in dark rooms. More durable colour prints are for example Dye transfers and Fresson prints, which are pigmented.
When it comes to digital printing, a delicate balance must be struck between printer, paper and ink. Ink is composed of two elements: chemical colours and pigment for durability. The first and still frequently used digital printer is the IRIS printer. Prints made by this machine are called Gyclée prints. Gyclée is a term invented by the manufacturer of the IRIS printer, to suggest a superior quality (in French Gyclée means ‘spraying’). Nowadays there are many great digital printers on offer, for example made by Epson. It is important that professional photographers keep a log of every print and which materials were used: the type of printer, paper, the inks and the finishing processes. For example, it is very difficult for photo restorers to tell the difference between a watertight and a UV coating. The only thing that is certain is that digital prints are sensitive to ozone and air pollution and that they therefore must be exhibited in clean spaces. Since no digital prints are currently old enough to study them, the durability of a digital print is yet unknown. Time will tell how well these prints can be preserved.