[ Download the PDF version of this file. ( 148K ) ]

Technical Bulletin 2-4/96

In addition to the original color set of transparent yellow, cyan, magenta and black, two additions to the Matchprint™ positive product line are now available: yellow-opaque white and yellow-opaque gray.

What are the new yellow sheets and why use them?

The new yellow sheets are designed to render a finished proof with lower dot gain than a proof made with the transparent yellow sheet. This lower dot gain better simulates SWOP standards for publication printing. SWOP is the acronym for Specifications for Web Offset Publications.

The color and density of the new yellow sheets are the same as the transparent yellow sheet. The lower dot gain results from a colorant added to the adhesive layer of these yellow sheets. The only difference between the new yellow sheets and the transparent yellow sheet is the adhesive.

* The yellow-opaque white sheet provides a background that simulates commercial base (independent of the base the proof is laminated on)

* The yellow-opaque gray sheet provides a background that simulates publication base (independent of the base the proof is laminated on)

The opaque colorant in the adhesive layer of these yellow sheets reproduces images on a finished proof with lower dot gain than images reproduced with the transparent yellow sheet. The total dot gain difference depends on screen ruling and color laydown sequence.

How does using these new yellow sheets affect the proof-making process?

The opaque adhesive layer of Matchprint™positive yellow-opaque white and yellow opaque-gray affects size, laydown sequence, exposure and base/background color. Processing is not affected.

* Size: New yellow sheets are smaller than transparent color sheets

The new yellow sheets are smaller than the transparent color sheets to ensure problem-free lamination. The smaller size minimizes any excess adhesive from sticking to the rollers during lamination, but does not affect the size of the finished proof.

If these new yellow sheets are cut down, the final size must be at least 1/8" (3.2 mm) smaller in both length and width than the other colors.

* Laydown sequence: YMCK

Yellow must be the first color down. Any layer(s) beneath one of the new yellow sheets will be masked by the opaque adhesive.

* Exposure: Use approximately twice the value for the yellow layer

These new yellow sheets require approximately twice the exposure value normally used for transparent yellow. Using either of the new yellow sheets does not affect exposure of the other colors. The standard lamination, exposure and processing steps remain the same for the magenta, cyan and black layers of a Matchprint™ positive proof.

The following exposure recommendations are the same for all colors, including the new yellow sheets:

10-step gray scale:
Optimum exposure produces an open Step 4 with the scale wrong-reading.
(Disregard any ghost steps.)

Microline resolution using the 3M™Matchprint™positive color element:
Optimum exposure provides a reading of 2 ­ 6 microlines while holding the 2% and 98% dots.

* Base/background color: Laminate the new yellow sheets to 3M™ Matchprint™ commercial base

The opaque adhesive in these yellow sheets provides a background color, or surround, that affects the appearance of the finished proof. To provide the best simulated color match to existing products, laminate Matchprint™ positive proofs made with either yellow-opaque gray or yellow-opaque white on Matchprint™ commercial base.

Once a proof is made using either of these new yellow sheets, the logo imprinted on the back of Matchprint™ base material will no longer accurately indicate the type of proof.

To help identify these proofs ­ or any Matchprint™ proof ­ use of self-adhesive 3M™ Matchprint™ stickers (#77-9803-8098-2) as a label for accurate proof identification is recommended.

3M is a trademark of 3M Company.
Matchprint is a trademark of Imation Enterprises Corp.

Copyright 1996 Imation. All rights reserved.