what is ink proofer and its functions

offset printing ink proofer

A proof is one (or a few) copies that show how a print job will look. Proofs originated in commercial printing, where the lithographic, gravure, or flexographic presses take a lot of work to set up. The idea was to print a fast, economical single copy of a job to show the customer, before spending the time and materials to make printing plates, ink up the press, and adjust ink and water balance-only to find that the customer didn't like the color.

As low-cost color printers were developed, designers and photographers also began making their own proofs. Today, proofs can be divided into two types, depending upon how they're used:

• Contract proofs show the appearance of color, or how photos will look when printed. The customer may be asked to sign off on the proof, indicating his or her acceptance of the job, hence the term "contract proof." Contract proofs need to be highly accurate in color.
• Preproofs, design proofs, or "comps" show early design stages of a job. Depending upon the stage at which they're made, preproofs may or may not need accurate color. Preliminary comps are economical prints mostly for internal use, usually from a desktop laser or inkjet printer, that show early design stages of a job, such as layout, position, and general color appearance. This type of preproof may not need accurate color. Final comps, used to present finalized designs to customers, may need to provide higher quality and more accurate color matching.

Quick History of Proofing
The first proofs were made on special "proof presses" that were separate from the production press and a little easier to set up. In the 1970s press proofs were replaced by laminated photographic systems like DuPont Cromalin and 3M Matchprint. In the early '90s continuous-flow inkjet proofs like IRIS and DuPont Digital Cromalin began to replace analog proofs. Customers who wanted halftone dots and press-like color began using digital dot proofs like the Kodak Approval and Creo Spectrum. In the late 1990s, large-format inkjet proofers, which had been considered too low in quality to use as contract proofs, made major quality advances and, with color management, have made large-format inkjet proofs the most common type of contract proof today.

FUNCTION

1. Spot color proofing

The multi-segment color mixing simulation machine can print color bars of different colors or the same ink color bar of different ink layer thickness at the same time, and can also print new and old ink on the same material for comparison, providing high-efficiency color comparison.

2. Four-color ink testing

It can test color hue, gloss and color concentration of ink, helping to control the quality of printed products basing on control of raw material quality.

3. Sample printing for pre-printing review by customers

It can print simple color bar for pre-printing review or filing by customers.

4. Testing color change of dry and wet ink

It can show required spot color ink color bar, and forecast the color hue after drying of the spot color (for example, purple and dark blue may turn reddish after drying, and this can be solved before printing).

5. When used together with a quantifier, it can forecast the consumption quantity of spot color ink, helping to greatly reduce residual ink waste and stock. It can also forecast ink transfer quantity and ink layer thickness.

6. Data-based management

When used together with spectral density meter, it can provide a data report on the color bar measured (Lab value).

7. When used together with other related instruments, it can forecast wear resistance, drying time, light resistance, heat resistance and other features of ink.