Wax Transfer Printers for Customizing CDs
If you only have one or a few discs to customize, but you want silkscreen quality, you have two choices: use a "generic" silkscreen design and add customizing information to each of them, or use a wax transfer printer. Since unique designs with silkscreen-like quality are required for some applications, wax transfer is an important component of the CD customizing lineup.
How does it work?
Much like inkjet printers, the wax transfer printer connects to a microcomputer and uses a special program provided to drive the printer. The technology is thermal transfer using a line printer. Either plain lacquered or "printable" (matte finished) media can be printed with these machines, unlike inkjet printers which require special printable media.
As with the other labeling methods, there are a number of factors to consider before deciding to use wax transfer:
At 300 dpi and with a completely opaque, glossy look, the thermal wax image is very simliar to silkscreen output, with the difference that only one color can be printed at a time, and the range of colors available is limited: at this time only black, red and blue are offered. Since changing colors requires changing the ribbon, it is not easy to prevent mis-registration when overprinting a second color, but with care this can be done. For monochrome designs printed in low quantity, it doesn't get much better than this. It is also possible to use a more colorful pre-silkscreened design in combination with wax transfer customizing. Since the resulting image is of comparable quality and appearance, this provides a seamless solution to those who need colorful but unique presentations.
A three-color ribbon version is available, but the resolution is quite low (still 300 dpi, but that's actually 100 dpi per color), so the results are not pleasing to everyone.
Wax does not smudge when rubbed, or bleed when wet. However, it is possible to scratch or chip bits of the wax design off the disc if it is handled carelessly. (You can do this to silkscreened designs, too, although not as easily.) If a disc is handled carelessly enough to chip some of the wax off, other damage could result, too, such as scratches to the protective lacquer and metal layer that can destroy the disc's usefulness. Discs given appropriate care should not have this problem.
The wax and pigments used in these devices are chemically inert. There is no deleterious effect on the media from outgassing or leaching. The only other potential for damage from using this method is from the heat required to transfer the wax onto the disc, but even this is not a serious problem. The disc remains exposed to elevated temperatures (the wax melts at 80 deg. Celsius) for only about 20 seconds, and most of this thermal energy is reflected away by the gold layer before it reaches the heat-sensitive dye anyway. Using this printing method should not have any adverse effect on disc longevity.
For information about the effects of heat and humidity on CD-R media, see the section on CD-R Media Longevity in this website. During testing CD-R media is exposed to much higher temperatures for much longer periods before it becomes unreadable. Since the combination of heat and humidity over time are the principal aging factors, limiting the time of heat exposure to such a brief period means the potential for damage by this printer is negligable. The same thing can be said for thermal inkjet printers -- using a disc printer is not going to damage your media.
The Rimage printer can be used inline with some automated disc duplicators. In fact, this was the first CD-R printer that was integrated with such a product. In mid-1995 the tray-loaded Perfect Writer was combined with Kodak's Transporter and the Kodak 6x recorder as a single "In-Line System" for premastering, duplicating and decorating CD-Rs without intervention required.
The major drawback to the wax transfer method is the cost of the printer. Materials (the printer ribbon) costs only about US$0.02 per disc, and plain lacquered media can be used, but the device has a suggested manufacturer's price of US$3,995, making this the most expensive desktop printer at the moment.
Wax transfer printing is safe, very attractive and, once the printer cost has been overcome, economical. The currently available printers of this type can label a disc quickly, in 20 seconds, and since they use a tray loading method, they can be combined with a disc duplicator for hands-off production. Wax transfer can use any blank media, and pre-silkscreened designs can be combined effectively with customization done by the printer.