Large Surface Engraving - Defocusing
For laser engraving large surfaces, intentional defocusing is sometimes better than processing the material perfectly 'in focus'. All you need to do is set the z-offset between 2 and 7mm, depending on the power of your laser machine and what kind of graphic you are using. By doing this, you will usually achieve a more even, professional-looking result. By de-focusing, grooves are avoided, and the end-result will have a smooth surface. The lens plays a very important role here too: for larger surfaces, it's best to use lenses with larger focal lengths. However, for fine details (4pt font), we would not suggest using any kind of z-offset at all.