Photographers and graphic designers are often tasked with the printing of photographic images, either by printing themselves or working with a lab or other service provider who handles the printing. In this article you’ll learn the fundamentals of the digital photo printing process as well as some procedures and best practices you can use to help ensure your photos come out looking their best.
Types of Photographic Printing
There are two main methods of photographic printing today: chromogenic and inkjet.
Chromogenic prints are the most common type of photographic prints. Also called C-prints and Type-C, these are the prints you get from the supermarket photo lab. But this doesn’t necessarily mean the process itself is low-quality — high end photo-labs also make chromogenic prints.
A digital C-print is made by exposing the digital image onto photographic paper that contains colored dye layers. The exposed paper is then processed with chemicals known as RA-4 that develop and fix the final image.
Because the process uses light-sensitive photographic paper, there is a fairly limited range of paper options, generally ranging from matte and semi-gloss to glossy and metallic. Some labs can strip the processed emulsion from a C-print and adhere it to canvas. C-prints are relatively inexpensive, and with care can last for decades without fading or discoloring; however, they are not generally considered to have long-term archival qualities because of the materials and chemicals used to produce them.
The equipment used to produce C-prints is extremely expensive, bulky and costly to operate and maintain, so it’s usually only photo labs that make these prints. Common brands of C-type imaging systems are Chromira, Lumira, LightJet and Fuji Frontier.
Inkjet prints are made using ink sprayed on paper. In the fine arts these are sometimes referred to as giclée prints. Inkjet photo printers range from very small, inexpensive models to large-format professional versions. There is an enormous range of papers available for inkjet photo printing; in fact, most any paper — and other substrates such as metal, wood and fabric – can be made inkjet printable by spraying on an inkjet receptor coating first.
Many inkjet printing systems can produce prints that may last for centuries without fading or discoloring, and high quality photo printing with inkjet printers is accessible to most photographers and graphic designers. For photographers, the most well-known and trusted brands of inkjet printers are Epson and Canon. Graphic designers also often use HP inkjet printers.
When you get a photo book printed, most often it’s printed using a digital press. These devices are more like large photocopiers than the photo printers described above; they use a plastic-based liquid ink that is electromagnetically bonded to the paper. Photo book companies such as Blurb use the HP Indigo digital press to print short-run and on-demand book orders.
As described in other articles on GraphicDesign.com, when you print a digital image, the color management system translates the digital color values in the image file to the color space of the printing device and substrate. It’s possible to print a single digital photo on any number of different printing devices and, with good color management in place, the prints “should” come out looking similar in tone and color.
However, each type of printing (and the type of paper) has inherent capabilities and limitations in the ability to reproduce different colors and the density of black. Inkjet has by far the widest color gamut, followed by chromogenic and lastly digital presses. So it’s possible that when you print the same photo on different devices there will be differences in the prints, especially if there are very saturated colors or dark shadows.
Note: the most important step in getting accurate prints is calibrating your monitor. I use and recommend the systems from X-Rite, such as the i1 Display and ColorMunki.
Using a calibrated display, soft proofing is a method for simulating on-screen what a photo will look like when it’s printed on a given printer and paper. Imaging software, such as Adobe’s Lightroom and Photoshop, can perform soft proofing.
Handling and Finishing
The way prints are coated, handled and stored makes a huge difference in how well they will stand the test of time. As soon as a print comes out of the machine it begins to degrade, and the rate at which the colors change depends on a variety of factors.
All prints can be coated or laminated, which increases their life-span. For C-type and inkjet prints, a lacquer-based spray such as Premier Art Print Shield is highly recommended — it can double the life of a print.
Prints should always be stored in dark, cool areas and away from solvents and airborne pollutants.