Digital C-Types (also known as ‘lambda’ or ‘lightjet’) use a digital-analogue hybrid process. This is the method used by high street labs nowadays, regardless of whether you supply them with a roll of film or a memory card. Traditional silver halide photographic papers are used in a machine that exposes the paper to light from LEDs or lasers that are directed by a computer, as opposed to the light transmitted through a negative in the darkroom enlarger. Once exposed inside the machine, the paper is passed through the same chemistry as that used in the traditional colour darkroom.
Since digital C-types are all but indistinguishable from C-type prints made from a negative in the darkroom, galleries and collectors will happily accept these kinds of prints. Although C-types are not absolutely permanent (we have all seen faded family photographs) and aren’t as resilient as black and white photographs to UV light, they have at least been ‘tried and tested’ in real life, rather than just in laboratory simulations.
Video Comparison of inkjet and C-type printing processes
Digital C-types are only produced by professional labs and institutions. The costs associated with setting up and running the equipment are very high and this is not a realistic option for most individuals. But many companies offer C-Types for less than the price of inkjets.
Different labs providing C-type printing use different machines and different brands of papers that will produce subtly different results and varying levels of quality. Some companies often offer postal services, such as sending test strips for you to assess, so you can instruct their technicians to make any adjustments to the exposure or colour balance before making the final print. They will then store the adjusted file for any future editions.
Lower-end C-types can also be ordered online at a greatly reduced cost with fast turnaround times.