Photo-quality printing in photo quality printing is saved in a CMYK file format to best utilize either the commercial printing process or inkjet printing photo quality output capabilities. CMYK dots of Cyan (blue), Magenta (red), Yellow, and Black are placed next to each other in specific patterns that trick the eye into seeing millions of colors. Photo quality inkjet printing transfers 4 or more toner colors to the substrate in a single cycle through the printer. In photo quality commercial printing each color of ink is applied separately. The high resolution photos are printed (or output) at a line screen value of
Early American editions of The Hobbit 14th impressions come in a variety of colors. Generally all the books from one printing are bound in the same color, but exceptions may have been found, perhaps when bindings intended for one printing were left over and found use at the beginning of the next printing. Hence the color of the covers cannot conclusively identify a book. The 6th impression's blue-green is medium light and distinctly blue. The 7th impression's khaki binding, on the other hand, shows no hint of blue or green. Its color is considerably darker than the 10th through 12th impressions. The rust color of the