Have you ever had a business logo or other favorite graphic engraved and was disappointed with the results? It may not be the engraver’s fault, or at least not entirely their fault. Not every graphic file is equal. My goal with this article is to provide just enough knowledge so you can get good quality engraving results (or etching of any kind) by providing the right file.
A large majority of people provide the engraving company a 72 dots per inch graphic file created for a web site. Engraving with this file is very unlikely to give you a result that you would be happy with. Your engraver should always point this out to you. If you use an online engraving web site to order a product and that company simply accepts your submitted graphic file without communicating with you, you are likely going to be disappointed.
The graphics below are of a USMC EGA Outboard that you may recognize. From left to right you will see the quality of the graphic deteriorate to the point you will get poor engraving results. The 72 DPI graphic is used on web sites because the file size is very small and when you open up the web page in your web browser, it open very quickly. When you choose this article, you may have noted that the graphics on the left loadd much slower. The “stair-stepping” you see on the 72 DPI file on the right is because the dots or pixels are larger and fewer per square inch creating a “stair-step” look. Many of these “stair-steps” are a shade of gray, even though the drawing of the art was pure black.
The laser engraver uses light to burn away the material. This light is very hot, actually burning away the material. A black dot or pixel burns at 100% power. Each shade of gray, as it gets lighter, burns with a lesser amount of power or heat. The variation of power or burning light creates lines that are not crisp. The lack of crisp lines can be very noticeable and look like jagged or poorly drawn lies…a poor quality look. Below are pictures and pictures describe it better than I ever could.
The bottom line…for engraving or etching of any kind, a pure black and white vector or 300+ dpi bitmap file should provide you with results that are professional looking.