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Print Surprise: Optical Illusions at the Press

 

 

Optical illusions – where the perceived reality of a viewed object is different than the actual physical attributes being viewed – are interesting phenomena. Occasionally an unintended illusion will pop up in the print work here at our shop, and it usually takes a little convincing to prove to our press operators and art department that the problem is in the viewing…not a mistake in the print files or print process itself.

Gradients Can Trick the Eye

Optical illusion on press sheets

Above is the press sheet layout for a 4-up printed card which will later be cut out and folded in half. However, coming off the press, the 4-up sheets appear like the left side is darker than the right, especially on the outer side of the card. (In person, the effect was even more dramatic than it shows up here onscreen as it was printing on a metallic paper.) We were stumped at first as to what could cause this – the pdf file was preflighted, all the images were rendering correctly. We wondered about a problem with the press, the imagesetter, the layers within the pdf file. Finally, it took cutting a finished sheet apart by the crop marks to see that once separated, the gradients looked fine. Placed next to each other, the light to dark gradient tricked the eye into thinking one side of the press sheet was darker.

Gradient optical illusion

 

 

 

Repeating Patterns and Distortion

repeating pattern optical illusion

The 2-up sheets printed above have a decorative border with a repeating pattern that flows in one direction to the halfway point and then reverses its orientation for the second half on all four sides. If you let your eye wander slowly along the borders, especially the longer vertical sides, it appears that the borders are bent and not a perfect square shape overall. The eagle eyes of our press operator noticed the subtle “bend” in the lines and decided that either the file or the imaging plate itself was somehow warped. Placing a ruler or straight edge on the press sheet reveals that, despite what your eyes are telling you, the line is perfectly straight across all four sides of the paper.

Optical illusion of a square decorative border

You can read more about optical illusions and view galleries of them at a surprisingly great number of websites as many people find the tricks our eyes can play on us to be a fascinating topic.

 

Call us at 828.684.4512 for any marketing needs. As a printer, we understand communication and design. Your printer should be able to provide you with the latest information, inspiration, technical advice, and innovative ideas for communicating your message through print, design and typography, signage, apparel, variable data printing and direct mail, integrated marketing and environmentally responsible printing. If they can’t, you have the wrong printer! The best advice, always, is to ASK YOUR PRINTER!

ImageSmith is now partnered with Extreme Awards & Personalization – our in-house partner providing custom engraved trophies and awards for employee recognition programs, sporting events, and promotional needs. With our new sister company, we will be sharing space, resources and expertise in a collaboration designed to further provide you with one place to meet all of your marketing needs… Under One Roof! Visit them online at www.extremeae.com or call direct at 828.684.4538.

 

 

Call us at 828.684.4512. ImageSmith is a full-service print and marketing provider located in Arden, North Carolina. Contact us at ImageSmith for quotes on all your print and marketing projects, and more useful tips on how to create custom, effective, high impact marketing solutions.
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Retro Gizmo: Artifacts from the Pre-Digital PrePress Department

 

Light Table, Prepress Department

Last year we featured a blogpost on an antique piece of bindery equipment still being used in our print shop. Today, we’re thinking about a few other vintage relics that have been gathering dust in the art department. The pre-digital days in prepress were not all that long ago – extending into the 1990s. The print industry was an early adopter of computer technology with digital imaging technologies, workflow and of course design software from the early days of Adobe, Quark, Corel, Aldus and others. Early Macs were the industry leader in digital typesetting, page layout and graphics. Both the design process and the photographic techniques used to image plates for offset printing underwent a rapid transition just before the new millennium.

The 90s saw the tail end of prepress imaging techniques that had evolved over decades.  Design skills included “paste-up” – manually positioning type and graphics onto each master sheet for printing. You’ll really appreciate a straight tool line once you paste on a piece of tool-line tape by hand! For graphic elements and photographs, anything other than 100% black had to be rasterized by imagesetters into “dots” to create grayscale halftones. Full color printing required four separate pieces of developed film, “stripped” into exact position with a hand-trimmed mask. Large print shops had many full-time employees whose job was to “strip” plates for the press, usually at light tables like the one seen at the top of this post. Below are some relics from those days when graphic design was as much craft as art:

Scale for enlargements
Resizing graphics and text was often done photographically before desktop publishing – requiring some math skills for percentages of enlargement or reduction. This handy tool was invaluable.
Pre-Digital Artroom Supplies
Paste-up: manually creating a master of the printed page. Red Litho Tape was used to block any light shining through a stripping sheet. “Cold Type” supplies included decorative tool lines in the form of tape. E-rulers were handy for measuring point size of imaged type.
Art Room Supplies
Strippers were small metal tabs used to keep film in perfect alignment for processing plates. It was also the name for the folks who handled that entire process. The orange sheet here is a stripping sheet, where printable areas would be opened up (masked) to allow photographic imaging of the press plates.
T-Square and grayscale or color targets
Manual skills and a steady hand were essential skills for paste-up. The T-square and other tools helped. Also, much of the imaging process relied on traditional photographic techniques to achieve proper color and grayscale output.

 

The skill and craft of fine printing and effective marketing is more alive today in the digital world than ever before. Strive to buy your print locally! A community printer will understand communication and design, with a special emphasis on your local market. They should be able to provide you with the latest information, inspiration, technical advice, and innovative ideas for communicating your message through print, design and typography, signage, apparel, variable data printing and direct mail, integrated marketing and environmental responsible printing. If they can’t, you have the wrong printer! The best advice, always, is to ASK YOUR PRINTER!

Call us at 828.684.4512. ImageSmith is a full-service print and marketing provider located in Arden, North Carolina. Contact us at ImageSmith for quotes on all your print and marketing projects, and more useful tips on how to create custom, effective, high impact marketing solutions.