Once these factors have been taken into account you can make a decision on which CD printing is most appropriate for your specific project.
Let's look at each of the processes in turn and their pros and cons.
Digital CD printing
This CD printing method uses a printer that uses the same process as an inkjet printer that many home users will know. In fact many home printers can be equipped with a CD print cartridge for use with pre-made CDRs with a printable surface.
CD screen printing is ideal for artwork that imparts massive color areas. Screen printing is performed with a machine with a rotating bed that has 5 separate stations where another color can be applied. The CDs can have a base color applied first across the entire disc area which means that a screen-driven CD design can consist of a total of 6 different colors at maximum.
The ink used in the CD-ROM printout is UV-sensitive and when each color is applied to a station the disc moves under a UV lamp as it rotates to the next station. The UV lamp binds the ink and this requires only a moment of exposure.
As the process name suggests screen printing is applied using very nice network screens. There is a separate screen for each color in the artwork's design. To create a screen a movie is produced that has the areas where ink is not applied to the disc blacked out. The new screen is initially coated with a thermal emulsion. The film and screen are aligned with each other with the help of stamp marks and placed in an exposure device. When exposed to a hot strong light the area of thermal emulsion is not protected by the dark area of the film. The screen is then washed with a water spray and the areas of uncured emulsion are washed away to reveal the net.
This printing process differs very differently from the screen printing process and the two typewriters are structured very differently. The lithographic process utilizes the fact that the ink and water do not mix much like oil and water.
The art image is applied to a lithographic CD typewriter using a laser. The printing plate surface is coarse in texture and pre-treated with a thermally reactive emulsion.
The pressure plates are treated using chemicals to allow removal of the exposed area of the thermal emulsion from the pressure plate. Once the printing plate has been prepared the area containing the artwork image is ink-receiving and water-repellent. The areas on the CD writing disc that are not printed are made to attract water but not ink. The pressure plates are then mounted on a rotary cylinder on the lithographic printer.
When the pressure plate passes through each rotation it passes over a set of rolls that apply water to the plate the water is attracted to the coarse surface where ink should not be applied to the disc.
Then the writing pad passes over the rolls of ink being added. The ink is attracted to the flat surfaces of the printing plate. A cylinder wrapped in a rubber blanket then rolls over the plate and picks up the ink.
Lithographic printing is perfect for printing photographic images because it can handle areas with subtle color gradient very well. However it is not good for large areas of solid color because there may be a difference in color detection that can lead to a spotty print on the CD.
As with CD-ROM printing lithographic printing has a fixed installation cost regardless of the number of colors involved in printing. It will only be economically profitable for printing runs of 100 discs or more and the more discs print out the lower costs the unit cost.
It is very important to present your supplier with as high a resolution as possible. The better the quality the image the better the quality becomes the final product. Make sure you check that all images especially photographic images are in their original format.
Make sure dark photographic images print well by running test prints before committing to the production run. If the image is printed the vendor will provide a panton reference code for each of the colors in the artwork so the print will be displayed exactly as you expect. If you already have a printed disc and you are looking for a recurrence ask your supplier about color matching. Most providers will provide this service and it will make you peace and quiet that the end product will remain compatible with previous projects.