HP Designjet PostScript Printers - PostScript Level 3 Fonts and General PS Level 3 Information

Smooth Shading feature renders gradient fills at the resolution of the printing system, reducing print time and improving output quality. Smooth shading significantly reduces banding from desktop printers and eliminates it entirely on high-resolution devices such as imagesetters and direct-to-plate systems.

Masked Images feature replaces complex clipping paths with a raster mask. LanguageLevel 2 commonly defined masked images by drawing a clipping path between the pixels of the source image. This method often resulted in limitcheck errors when saving or printing complex or multiple clipping paths. The masked images feature in PostScript 3 lets you place images on the page without concern for the constraints of the clipping path. Instead of mathematically tracing each line segment, the masked images feature indicates which individual pixels in the image should be masked.

Selectable Separations feature lets you print color separations, even on low-end monochrome printing systems. A "separation" is the output that corresponds to one color plate (e.g., cyan, magenta, yellow, or black). In the past, only imagesetters could generate separations as individually imaged pages. Other printing devices depended on the host computer to produce the imaged data for each separation. With selectable separations, you can perform basic proofing of separations without having to output to film, saving time and money.

More Gray Levels feature lets you print photo-quality grayscale (256 gray levels) images on monochrome desktop printing systems. Although PostScript interpreters can handle 256 gray levels, most desktop monochrome printers can print only 32 to 72 gray levels. PostScript 3 uses "supercells" that increase the number of printable gray levels by a factor of four. This technology also helps high-resolution devices such as imagesetters print 4,096 shades of gray in each colorant to produce images with smoother blends.

In-RIP Trapping lets you use a raster image processor (RIP) to perform trapping rather than a page layout or post-processing application (e.g., DK&A Trapper). You can specify regions on a page, called trapping zones, and specify a set of trapping parameters, and then use the RIP to calculate and administer traps for each region. For print service providers, for whom built-in color trapping was previously unavailable, in-RIP trapping saves time and money by eliminating the need for manual, labor-intensive trapping processes in proprietary and expensive systems. In-RIP trapping is an optional PostScript feature, so not all PostScript 3 devices support it.

HiFi Color lets you specify and render more vibrant hues and richer colors than in previous LanguageLevels HiFi color specification lets applications such as Adobe PageMaker 6.x transform data into HiFi color spaces (e.g., Pantone Hexachrome) prior to printing. HiFi color rendering performs color transformations in the PostScript interpreter, reducing print times.

Improved Color Control provides greater control for overprinting color components. This feature introduces the DeviceN color space, which allows the composite specification of an arbitrary number of device-dependent color components (e.g., cyan, magenta, and yellow). Previously, to alter only the cyan, magenta, and yellow device color components and leave the black component unaltered, you needed to use the Separations color space, called DeviceCMYK, once each for cyan, magenta, and yellow component.

Idiom Recognition converts less efficient LanguageLevel 2 operators (e.g., application-generated contours and iterative shades) into higher-quality, faster-printing PostScript 3 operators.

Fast Image Printing lets you print raster images in fast draft or near-final quality modes. This feature optimizes images and speeds printing by inserting device-specific halftone values.

Compact Font Format (CFF) is a compact representation of one or more Type 1 (PostScript) fonts. Unlike previous PostScript font formats, CFF allows multiple fonts to be stored together in a unit called a font set. CFF significantly reduces required disk space of fonts by using a compact binary representation of fonts and by sharing data that is common to multiple fonts.

Chameleon Font Format uses a "shape library" which allows compact representations of Roman font shapes for book and display faces. Chameleon fonts can be tailored to address the font needs of a device.

Extended Font Set increases the number of standard fonts. While there is no standard set of required fonts, Adobe PostScript 3 devices typically use an extended set of 136 fonts that are built into the PostScript interpreter. LanguageLevel 3 has defined a new character in the Symbol font set and has added Central and Eastern European (CE) character encodings to PostScript character sets.