My second project has now been completed. The images were all .svg files that I had to convert to jpeg files before Luban would accept them. The power was set at 60% and the lesson I take away from this set of example images is that the constant power setting does not mean that each image will be produced with constant results.
I cannot begin to understand why some of the images do not look as they were engraved by the laser beam at its 60% power setting. They may have been etched on different days so possibly the atmospheric conditions may have affected the images.
The image on the bottom left looks to be the one which has taken the laser beam the most easily. The next 3 along the bottom row look to be even for power and etching similarity. The second image on the middle row looks to be quite light in comparison to the other images on that row. The middle two on the top row also seem to be a little lacking in power. Maybe the wood was made of very different quality. Possibly dampness has crept into the wood store.
How and ever, here are 12 coasters made from laser cut plywood that is 2mm thick. Any suggestions as to how to keep the applied power of the laser at the chosen setting would be helpful.