Product

Platform

Operating system

Error

Symptoms

If I make a proof through Prinergy's proofing process plan (for example, HP-RTL output) will this be a screened proof?

For which proof output formats do I screen and for which ones not ?

Cause

Solution

It depends on the proof. Screening is used for all bilevel output formats, designated by selecting Shades=1 in the Render tab. What you can see if you have both the Render and Screening/Calibration tabs open at the same time is that if you choose an output format where you have the choice of selecting either Shades=1 or 256 (1-bit halftone vs. 8-bit contone output), selecting Shades=256 will always gray out most of the Screening/Calibration selection controls.

Many output format types (EPS, TIFF, etc.) allow you to choose between screened and unscreened, or contone, output. Some force you to stick to one type. For example, HP-RTL, Epson, and VPS output is always Shades=1, or screened, output. Scitex-CT is always Shades=256, or contone.

The Prinergy Proofing Connectivity Tech Library page (http://intranet.creo.com/support/html/workflow/proofing_connectivity/prinergy_proofers_index.htm) describes the proof output format for the proofers officially supported by Prinergy.

Note that setting Shades=1 does not imply anything about the number of gray levels that can be shown by the screened output; it just means that the output will be 1-bit data.

In general, 8-bit contone data streams are about 8 times as big as 1-bit screened data streams (actual difference depends on compression scheme used), so 1-bit output is preferred in applications where network bandwidth is an issue, provided Prinergy supports 1-bit output to the device in question (i.e. it's been tested and quality is acceptable to the customer). All high-res devices (1200 dpi and up) are driven with 1-bit, screened output. Lower-resolution devices are preferably driven with 1-bit output, with contone (8-bit) output used only when quality of the 1-bit output is unacceptable to the customer. The usual tradeoff is a big performance hit, both in network transfer time and in the time taken by the low-res device to process the contone data. Note that the Prinergy RIP itself (CPU-wise) performs similarly for contone and halftone data; the bottlenecks tend to be network transfer or disk caching of the large data streams, and consumption of the data at the device.

Permanent fix:

See also

Keywords

proofing, screening

Technical contact(s)

Rob Prior

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Date submitted