Today, with new ceramic toners and commercially available digital technology, high-quality, continuous-tone decals can be printed easily and quickly. Short runs and even one-offs are economically possible. Using digital decals, custom-decorated products, prototypes and personalized ware can be manufactured at a reasonable cost.
Digital ceramic decals are printed using a four-color process-cyan, magenta, yellow and black (CMYK). To achieve good color management on ceramics, the four selected colors must be of the proper color strength, tone and refractoriness so that they work well both individually and in combination. This allows the widest possible color gamut (color space) while ensuring that the mixture color is consistent and reproducible. For the color green, for example, the yellow and blue (cyan) must be of the same refractoriness and the proper color strength and tone to yield a wide gradation of green shades and hues. The green must vary predictably with the total amount of color printed and with the relative amounts of blue and yellow deposits making up the final color. The new toners were specifically created to achieve these properties.
The new ceramic toner system meets the vast majority of printing requirements, including portraits and landscapes. Recently, a selenium-based palette was also added to the color mix. The modified four-color system produces a somewhat different color range, including true red and orange hues. With the properly engineered cover coat systems, the ceramic toners meet even the stringent requirements of California's Proposition 65.
Since the image files are rather large, the user should have a fast PC or Mac with a large amount of memory and a high-quality monitor designed for graphic work. Software for image manipulation and desktop publishing is also required.
After image adjustments are complete and the decal sheet has been previewed on the computer monitor, the data is sent to a color server, which manages a laser printer. A relatively high-end copier and printer, such as the Canon 900, is recommended to produce digital decals. When used as a copier, the machine can print decals directly from images placed on the glass. When used as a printer, the color server manages the data and the printing process, freeing the PC or Mac for other tasks.
With ceramic toners in place and water slide decal paper in the carriage, printing begins. A3 (11 x 17 in.) paper is currently the largest size that can be used to print digital decals.
After printing, a cover coat is applied to the decal paper to protect the printed image and to allow the print to be transferred to the ware. The cover coat, which can include an optional flux, can be applied using special heat release cover coat sheets. The sheets are placed on the print and are run through a laminator to transfer the cover coat to the print. The cover coat can also be applied by conventional wet screening over the decal sheet. If necessary, a screen can be made to cover coat only the actual image.
Once the cover coat is in place, the water slide decal is ready to be applied to the ware and fired. The ceramic toners are designed to be fired on glaze at 800C, enabling them to be used on fine ceramics. The 800C firing also allows digital decals to be used as surface decoration on porcelain enamel and borosilicate glass. The entire printing and coating process typically requires only one to two minutes to complete.
Samples or prototypes can be quickly produced and presented to buyers, focus groups or management. Adjustments to the color, size or overall image can be easily made, and corrections are just a click away. Additionally, the images achieved by the 300 dpi printing are near photographic quality. For comparison, a typical TV monitor displays at about 72 dpi (or pixels per inch), and a typical magazine picture is printed at about 266 dpi.
Production space requirements for digital ceramic decals are also minimal. A 12 x 12 room can easily contain the scanner, computer, server, copier/printer and laminator, thus becoming a mini-factory. Approximately 1400 A3 sheets can be printed in an eight-hour shift (at 3.5 pages per minute). Since six wall tile-sized images will fit on a single sheet and since each image can be different, up to 1400 decals of each motif, or 8400 total decals, could be printed for decorative tiles. Depending on the image size and coloration, a single set of toners will print 4000 to 6000 A3 sheets. An office-sized space can typically be fully equipped with purchased and/or leased equipment for less than $20,000. For companies that prefer not to invest in their own equipment, digital decals can be obtained from some decal producers.
As digital printing develops and adjusts to the specific needs of the ceramic industry, the cost reductions and increases in speed, flexibility and quality enjoyed by others in the printing industry will also become available to the decal producer and decorator.
Design Point Decal supplies both conventional screen-printed and digitally printed decals, and also supplies the new digital decal printing technology to companies interested in producing their own digital decals in-house. For more information, contact the company at (914) 935-3300, fax (914) 935-3310, e-mail email@example.com or visit http://www.designpoint.com.