Awards & Engraving

October '18

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20 a-e-mag.com • A&E OCTOBER 2018 YOUR LASER AT WORK By Jim Puentes Much like writing with chalk on a blackboard, the laser vaporizes the coating and exposes the stainless steel underneath, making a light contrasting mark on the tumbler. What's black in the drawing trans- lates to stainless steel on the tumbler and a negative image is engraved. In order to create a positive image, the graphics in the drawing need to be inverted. The subject of inverting graphics is easy enough to understand. Many may ques- tion the need for an article on something so basic. But I've seen enough examples of completed works, done by skilled craft people, that failed in this regard, so there must be some confusion regarding it. Hopefully this article helps. A DARKER OR LIGHTER MARK? Before anything is marked with the laser, there is one question to consider: Will the mark that is made, even if color-filled, be darker or lighter than the material being marked? If darker, there is no need to invert the graphic. If lighter, then inverting the graphic in the drawing may be necessary. I qualify this because many graphics, particularly text, borders, and simple clipart, look just fine either way. Gray- scale graphics, photographs, and more complex graphics such as those where re l a t i v e c o l o r s a n d c o n t r a s t s n e e d to be preser ved should be inverted. "If the mark or fill is light, invert the graphic to get it right. But if the mark or fill is darker still, the graphic should stay in a positive way." When a graphic is engraved with the laser and makes a mark that is lighter in color than the material being marked, a negative image is created. Text that is black in a drawing will be white on a wineglass. A positive image of an American flag in Y ou've been marking school logos on stainless-steel tumblers using laser marking material for months. They all turn out great, with a dark contrasting result. Then you're given some black powder-coated tumblers to mark. No problem. Using the same graphic, you run a job that vaporizes the color to expose the stainless steel underneath. You clean it up a bit and… it doesn't look quite right. It looks like a negative! What just happened? To Invert or Not to Invert Jim Puentes opened COOLaser- Craft in 2008, providing his cli- ents with marking, cutting and fabrication services. Contact Jim at jptreeman@sbcglobal.net. How to invert graphics for laser engraving When a graphic is engraved with the laser and makes a mark that is lighter in color than the material being marked, a negative image is created. For example, a bald eagle will have a dark head and a white eye on a dark-colored, cotton duck canvas bag. ALL IMAGES COURTESY JIM PUENTES

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