(v13) The HqnWhite procset

This page applies to Harlequin v13.1r0 and later; both Harlequin Core and Harlequin MultiRIP

Color-Logic Inc produce technologies that support graphic artists in designing work that uses various metallic effects. That work can then be printed on conventional presses using silver ink, but it can also be printed on a digital press that includes an opaque white colorant onto a pre-coated silver-colored media. In essence the “silver” channel in the job is printed in negative using the white colorant, so that the silver media only shows through where the job requested silver.

The following overprinting controls and a framework can be called from your code around the RIP to accept a job containing a silver separation and to invert that separation to white output, for printing on silver media. This code could, however, also be used for any similar situation where a separation must be inverted.

Prerequisites:

Device with white colorant.
White colorant has KnockoutType set to 0 .

Note: HqnWhite is not currently compatible with Harlequin VariData or in-RIP imposition. The entry point is the InitWhite dictionary which can contain:

`SourceColor`	(String, name or array of strings and/or arrays) (Optional). The color names to invert to the output white If missing defaults to (CL 4713 SILVER).
`ForceUpperCase`	(Boolean) (Optional) If `true` all values in `SourceColor` must be uppercase and all simple alphabetical characters in candidate spot color names will be converted to uppercase before comparison, in other words the lookup will be case insensitive.
`DeviceColor`	(Name or string) (Required) The device name for the white colorant.
`BlankWhite`	(Enumeration) (Optional) What to do if no marks are made by this procset on the white separation: `/Render` just go ahead and render anyway (default), `/Error` trigger an error (you probably have the wrong media loaded for this job), `/Warn` as `/Render` , but issue a warning, `/Omit` try to omit the white separation, may fail in some configurations, `/Custom` trigger a custom procedure to be run at `StartRender` .
`CustomBlank`	(Procedure) (Required if `BlankWhite` is `/Custom` , ignored otherwise) Called at `StartRender` time if white separation is blank.
`WhiteBleed`	(Number) (Optional) Width in points of extra bleed for white area to be added around “pages”. Default is 12 points.

Note: HqnWhite is not compatible with HqnImpose2.

An example of the calling code is shown below:

TEXT

  <<
  /SourceColor [
    (CL 4713 SILVER) % Color-Logic (SILVER)
    (ARGENT) % French
    (ARGENTO) % Italian
    (SILBER) % German
    (PLATA) % Spanish
    (PRATA) % Portuguese
  ]
  /ForceUpperCase true
  /DeviceColor /SpotColor_White % This must match a colorant name on the device ... or it will be added automatically.
  /BlankWhite /Warn
  >> /HqnWhite /ProcSet findresource /InitWhite get exec

In Harlequin Core this code would be called from a configuration stream. In HMR this would be called from plugin PostScript language code. It can also work as a page feature.