Hello! I am having a strange problem - I am trying to engrave a photo on wood. When the wood is rough (like the first one in the photo), then shades of gray are produced.
But when wood is sanded with sandpaper, then it’s either black or nothing. I tried different speeds, different laser power - still the same result.
I have a terribly silly question, just to be sure.
after you have sanded the wood, do you blow the sawdust off properly?
What typre of wood are you engravng? Some types workbest with a coat of bycarb soulution whch enhances the burn. Also what are your speed and power settings? .
When you have untreated wood, the “surface” is much larger. All the fine upright fibers are easier to burn with the laser than a “hard and closed” surface.
It requires more fine-tuning to make gray tones more visible. You will not often see true grayscale on e.g. glass, made with a “normal” laser. Here, other techniques are used which simulate gray tones.
It may not be the most scientific explanation, but it’s my best bet.
I assume you are in grayscale mode… what is the dpi you are trying to achieve?
pine board
Yes, I wiped it.
The settings on both are 200 dpi, 1100 speed, 100% power.
Maybe…What laser are you using? Speed in mm?
your not specifying your power range so we have to assume you are talking about dithering instead of actual “gray scale”. if you are using a diode laser they will be far more sensitive to the reflectivity of the material since they are using light in the visual spectrum. When that’s the case, you need to treat the wood for a uniform base. The bicarbonate treatment was mentioned already.
Oh yes, it is dithering (visible on the picture). Shades of gray do not work at all.
How do I use bicarbonate on wood?
I have seen people use a light whitewash on the wood to get better contrast. I just don’t like engraving photos on wood; the results are typically unsatisfactory mostly due to wood grain.
PIne can be difficult because it is a real sappy wood that can burn inconsistant.
It appeared to me that two samples are made in different modes. Dithering is clearly visible on first sample and second looks like straight grayscale pass-though. It is impossible for wood, sanded or not, to somehow burn in such continuous lines if dithering is applied.
I would bet that somehow you have changed mode from dithered to pass-through grayscale for second image.
I’ve had excellent results on unsanded wood. But it was not pine.l
