As a Windows user who sometimes prints colour, I have a copy of the popular printing program QImage by Mike Chaney. A feature was recently introduced to allow people to selectively clear blocked nozzles without running cleaning cycles.
This intrigued me, as Qimage is not a RIP and uses the print driver, so how could it do this? Well, if you watch the support video (20 mins)
he confesses that he doesn't / can't do this. His view is near enough is good enough in terms of targeting a single colour.
But what is interesting is that this new feature uses what he calls a pulsating purge pattern. I've attached a screen grab from the video that gives a rough idea. Rather than printing a solid block of colour/black, as you might do if you were using a custom QTR curve to print a rectangle of black to clear a single channel, it prints a rapidly repeating series of narrow gradients, as per the attached. His argument is that this turns the nozzles on and off in rapid succession and increases its effectiveness. I confess that I've not tried it, but as someone who is currently wrestling with printers that get gaps in the nozzle check far too quickly, I am certainly interested.
Have you heard of this? Views?