Laser cutting tests and outcomes

I have now started the tests for laser cutting halftone relief images into perspex acrylic sheet. Some initial trials showed that the cutter could not resolve halftones that were any finer than around 21 lines per inch. I experimented with cutting speeds, cutting lines per cm and heat intensity.. The final tets had a setting of: 5mm perspex, 60mm speed and 85 laser power. This gave a result where I felt that I could achieve a relief print. Having now carried out intitial print tests it is clear that this process will work. There are issues around materials though: in cutting the halftone the laser seems to burn cutting debris which 'sticks to the halftone cut in the perspex. The result is therefore imperfect. To resolve this I am trying to strengthen (make coarser), the halftone structure and consider a linear halftone to compare with the dot screen. Having said this, the printed halftone gives a feel for coarse newspaper halftones before the advent of digital and litho preparation. I am going to persevere with the perspex; additionally I am going to test other materials in the laser cutter, such as MDF and some synthetic rubber/acetate material (which I'm not sure of the name of at present) used for lino cuts. My aim is to achieve bold, high contrast images which can then be either hand coloured, screen printed onto or collaged back into further image developments.