Henry & Thompson CD & DVD DISC PRINTING PROCESS EXPLAINED

The revolutionary thermal re-transfer disc printing process that delivers spectacular results!

Overview of Disc Printing Methods

Before the advent of thermal re-transfer technology, there were three ways of labeling CD and DVD discs. One was using a stick-on paper label, which made for colorful and crisp artwork, but was not recommended for archiving or use with high speed disc drives due to the adhesive (glue) used. Second was printing right to the disc surface, which required specialty inkjet or thermal printers, and printable surface media. Inkjet was colorful, but slow and, besides a tendency to smudge, subject to the quality of the disc's print surface. Thermal prints were much more cost effective and permanent, but lacked the necessary image quality on all but solid colour images, and the equipment was more expensive. Finally there was silkscreen, which could give a real professional look, but required expensive professional artwork preparation, and was only cost effective in large volume production.

Now, thermal re-transfer disc printing technology bridges the gap between thermal and silkscreen printing methods, bringing with it an indelible photographic quality output, white colour printing, and hub printing capabilities.

The Disc Printer we use at H & T utilizes this revolutionary new technique, called thermal re-transfer printing, where the entire label image is first transferred to a plastic transfer ribbon, one color at a time, with the final image re-transferred to disc. This process allows for printed products to be produced at the quality of silk-screen printing yet with the added convenience of being able to be printed on-demand. Also, for full-surface high-resolution labels, thermal re-transfer prints come close to those produced by inkjets and without inkjet-printing's limitations (smudging, reduced packaging options, susceptibility to humidity, etc.).

The Thermal Re-transfer Printing Technique

Employing "Micro Dry" technology, thermal "re-transfer" or "intermediate transfer" systems are more commonly used to decorate everything from fabrics (T-shirts) and ceramics (mugs) to metal (signs) and plastic (identification cards). To accomplish its task, the thermal re-transfer Disc Printer uses two separate consumable items, an ink ribbon and a transfer film, in its multistage printing process. The first step involves applying heat (from a thermal print head) and pressure (from a roller) to deliver solid-colored resins from the ink ribbon, advancing between its supply and take-up spool, onto the similarly configured roll of intermediate transfer film. CMY and CMYW ribbons contain separate panels for each colored resin and the transfer roll advances and rewinds for as many passes as are necessary to form the image.

Once the transfer roll contains the completely assembled image, labeling takes place by pressing the roll to the surface of the disc. Through the combination of heat (from a halogen lamp) and pressure (from a roller) the resins on the transfer roll are conveyed to the surface of the disc as a sliding tray moves the disc past the fuser assembly. During the process, the transfer film also surrenders layers that bind and protect the resins resulting in a completely smooth, water-proof, and extremely durable laminated finish.

In this way, the Thermal Re-Transfer Printer is able to print full color, photographic images to the surface of a CD or DVD, reproducing almost flawlessly any high quality image, and maintaining image accuracy and detail while keeping the color vibrant and the picture sharp. The final high quality printed product is so durable that pressure, moisture, or light cannot damage it. Images can also be printed from one edge of the CD-R or DVD-R/+R to the other – even across the hub – without loss of quality.

Printing quality

In addition to their permanency, Thermal Re-transfer Prints are photo-realistic, akin to those created by offset printing. Putting conventional thermal transfer and commercial silkscreen production to shame, the Thermal Re-transfer Printer forms images composed of variable-sized dots with an output resolution equivalent to 160 lines per inch (LPI). Whether printing photographs, vector or bitmap graphics, or text, the resulting prints are stunning labels with dense fields of color, photo-realistic images, and attractive text.

Beyond producing photo-realistic images, the Thermal Re-transfer Printer has several capabilities never before seen in desktop disc-labeling systems. The most dramatic is white printing on silver surface media. Significantly expanding visual possibilities, white may be printed by itself or as a background to which other colors can be applied.

Also unique to the Everest is its ability to print in the disc-clamping (hub) area, allowing labels to cover the entire surface. Beyond appearance, hub printing is useful in some applications for marking discs with serial numbers or other identification information.

Thermal Re-Transfer Compatible Discs

Because the Thermal Re-transfer Printer works by conveying colored resins from its printer ribbon onto its transfer roll and then fusing those resins along with donor layers of the transfer material onto the surface of the disc, only certain types of surfaces are suitable for thermal re-transfer printing. For the resins and donor material forming the label image to be successfully conveyed from the intermediate film to the disc surface, printing conditions must be such that the printed label favors adhering to the disc surface rather than the transfer film. This means that printing success or failure depends upon such factors as the chemical (composition of material, etc.) and mechanical (texture, flatness, etc.) properties of the disc surface.

Discs featuring surfaces specially optimized for thermal transfer printing are therefore required to attain smooth and attractive surface prints.