Most consumer inks are water-based dyes, ideal for applications where high-quality output is essential, such as photographs and drawings. Because of their formulation, however, these inks suffer from two major defects: first, they tend to bleed into the paper; and second, they are not colorfast and often fade over time.
The easiest way to solve the first problem is to use the right paper. Special inkjet-specific stocks are manufactured so that they do not easily absorb water, thus forcing the ink to dry on the surface and form crisper images.
For the second problem, you will want to look into archival quality inks, formulated with special pigments that resist fading and rely on a solvent other than water to make them waterproof. In addition, there are paper stocks specifically designed to resist yellowing and degradation for archival purposes. These tend to be sold with higher quality and more expensive photo printers.
Solid ink was originally developed by Tektronix, a company that was eventually acquired by Xerox, which today makes printers based on the technology.
Solid ink is a candlewax-like substance sold in small blocks—one type for each of the primary process colors that form images on paper (cyan, magenta, yellow, and black, or CMYK). Inside the printer, the ink is melted and squirted onto an oiled roller using a technology similar to that of offset printers.
The main advantages of solid ink printing are that it is fast, reliable, and environmentally friendly—inks are non-toxic and safe to handle. However, the initial investment is usually higher than that of a laser printer.
Although their photo quality is not quite as good as an inkjet, solid inks can be used to print high-resolution color graphics and generally make excellent office machines due to their low maintenance cost. (My office has had one for the last 10 years, and we’ve never had to service it beyond replacing the consumables.)
Toner is the ink of laser printers; typically, it is made by bonding a pigment to a polymer to create a fine powder with particular electrical properties.
Inside the printer, a laser beam “paints” the image to be rendered on a drum, loading it with an electrostatic charge. The drum then rotates over the toner reservoir, picking up particles of ink that are later transferred to paper and melted in place.
Toner is excellent in terms of durability and quality, especially for applications like printing text and line art. Once it’s fused to the paper, it doesn’t fade or come off easily. It doesn’t fare as well for photographs, however, where inkjet printers provide finer resolution and, therefore, better output.
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