Issue with PNG files and transparency


Hello, I have an issue using PNG images with transparency. I load a PNG image for a grey scale engraving. In the laser setting preview it show a correct picture without the transparent part but when I generate the g code an go to the work tab, it show ( and engrave) a dark rectangle instead of the transparent part. Can someone help me? Thanks in advance.


The transparent layer is ignored for a long time… Remove the layer will work for you, we’ve known this issue for some time and forget to fix it again :man_facepalming:. Put it on the todo list of next version, thanks for your reminding.




I am still experiencing the exact same issue that umbe0471 is describing. Could you explain what you mean by removing the transparent layer? What free software can I use to do what you are describing?




Were you able to resolve this problem? If so, I would love to hear how you did so. I am having this exact same issue right now.




PNG files have 4 channels: RGBA. the A stands for alpha channel (transparency channel) which adds the functionality to express transparent than use JPEG files.


As the figure above, the grey/white grids are transparent layer of the image. Snapmakerjs can not deal with the transparent channel, so you will have to remove the alpha layer and replace with white color in order to make Snapmakerjs know how to draw transparent colors.

Just search “png remove transparency” on Google and you will know the answer.


I use ToyViewer on the Mac for this - it’s a free download from the App Store.
After opening the file, select the “Effect” menu item and then the “Transparency” item,
which will bring up a Tool Panel display where you can deal with the transparency
in 3 different ways. By just clicking the ‘OK’ button by the "Remove Transparency"
area (the first one of the 3), it will by default change the transparency channel to white,
although you can change it to any other color. If you don’t select anything on the image,
the “Inside of selected area” and “outside of selected area” seems to have no effect; it
works on the entire image. You can then save or export the image as a png or other image
file format.