Dov Isaacs, principal scientist in Adobes Print Workflow Products Group, outlined his principles in a workshop at the Adobe Acrobat PDF Conference here.
The first principle, according to Isaacs, is, "the quality of an end-product directly reflects and can be no better than the quality of its source components." Taking care when selecting, preparing and assembling ingredients for a PDF is a key to success, Isaacs said, and he recommends that companies get professional training for those involved in the process.
Isaacs second guiding principle is: "Maintain content at its highest level of abstraction by category and within category." If information is in text form, it should be kept in text form for maximum flexibility rather than being converted to a vector graphic. Likewise, graphics are easier to manipulate than raster images, and live transparency and gradients are easier to control downstream than flattened transparencies and gradients are.
The third principle, according to Isaacs, is to "lose no data before its time. Add no unnecessary data." When fonts are converted or image data is downsampled then upsampled, the quality of the data deteriorates, he said. Likewise, color information should not be converted to device colors until late in the game.
Isaacs fourth principle: "Avoid unnecessary and cascading data and attribute transformations. If you need to rotate a graphic, for example, "rotate it only once, at the end," Isaacs said.