Laser burning through everything

#1

I have been trying to laser engrave but it seems to burn right through no matter what I do.

First I tried on 2 layers of corrugated cardboard - which is perhaps to thin so it burned through (and the paper beneath and a bit in the table).

Now I am trying on leather but it still burns through. First it was an all black symbol and I then tried changing it to a lighter shade of grey but with no luck. Now I have lowered the laser power to 20-25 (which is as low as it goes) and it seems okay (though it is a deep engraving) but in some corners where it still burns all the way through.

Should I just set the laser out of focus? Or am I missing something?

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#2

When the laser is well focused, it will generate high temperature, which can burn paper and leather through.
You can set the appropriate laser power to prevent excessive burning on the surface of the paper and leather.
Also focus by turning the metal knob at the bottom of the laser head to adjust the appropriate laser focal length, so that the laser focusing effect is not too good.