It is recommended to use the J-Tech firmware for raster engraving photos with our PicEngrave & the J-Tech laser for two reasons. First, it executes the S commands in real time without any dwelling. Second, it has the proper PWM frequency for the J-Tech laser driver.
Our PicSender streamer makes it easy to switch back & forth between the different versions of grbl firmware. For the laser to engrave photos, the J-Tech firmware should be used, then you can switch back to grbl 1.0c for spindle use or vector cutting with the laser. Here is information on how to switch back & forth with our PicSender.
We use 1/4" thick honeycomb aluminum with our 6W laser under our material for cutting. You can also lay something else none reflective under the honeycomb aluminum to protect your waste board.
I don’t have experience with inkscape, so I can’t answer that question.