As a follow on from the first post in this thread....
Nothing is ever simple and something that becomes apparent when we start experimenting with impact printing from GCode files is the phenomena of ‘banding’. When an image is mathematically processed to create a halftone it must not subsequently be scaled or have the aspect ratio altered in any way otherwise banding may occur. It does not always happen but when it does the result is a spoiled product – the following image was accidentally scaled and the pictures show the result. The, otherwise nicely distributed, dot pattern has formed into groups and suddenly they become noticeable.
Although I keep trying not to make comparisons, because of the entirely different method of operation, the Mach Impact / Laser plugin calculates the halftone dot pattern on the fly so does not suffer from this problem and even pre-prepared halftone images which have been scaled get corrected by the plugin at run-time so everything turns our right in the end.
Tweakie.