DPI and WHY
The difference DPI (dots per inch) make in laser engraving
As an engraving company in Kings Lynn, Norfolk we engrave lots of different types of material for many industries, but one of our favorite things to do is photo engraving. it's not as easy as it looks.
It's surprising to learn that more is not always better when it comes to engraving resolution.
In order to successfully laser engrave, you need to know what material you are engraving on. This is important because during the process of laser engraving, materials absorb energy. Due to the amount of heat involved, the dots will grow larger in size and on softer materials, overlap (dot bleed) If you're engraving a photograph onto wood the DPI should be quite low, I'd say no more than 300dpi. In the case of engraving aluminium, you would be working with a resolution of 500 to 600 dpi, and you could even print at a resolution of 1000 dpi! Just remember, the higher the DPI, the longer it will take to engrave.
All photos engraved on Trotec speedy 300 80w. Speed was set to 75% and power was at 40%.
The below photo is engraved at 125 dpi onto black anodised aluminium. As you can see here, the individual dots are clear to see, it still looks pretty good, just a bit dotty!
Now look at the same photo engraved at 300 DPI. The difference is very clear, there's more detail in the picture, the individual dots are harder to spot and the engraving looks softer and less harsh.
If we up the DPI to 600 we can again see a diference, the engraving looks lighter, everything looks softer and if you look closely you'll see more detail.
This final photograph is laser engraved at 1000 DPI. I don't think our laser setting where quite where they needed to be with this one. While we have gaines some detail, we've also lost some to the darkness.