GB Postal Franking dots

Hello. well actually dots is not technically correct as the marks are shaped.. as you can see from the scans.. same four stamps.. for some reason the first scan did not pick up the true colour of the dots .. which are light grey I might add.. and when I rescanned with different settings I got what is more a negative image and from which you can see the shape of the dots better.
anyway.. the dots or whatever you want to call them are from the franking machine as far as I know. I read an article on these some time back and for the life of me cannot find it, but I am guessing someone out there knows a lot about these postal markings. I am sure my mate Roy at MachinMania wrote about them.. or we spoke about them. The reason being, there is debate as to whether they are "proper" frankings to us purests that like to see a town and date cancel etc etc.. rather than some computer read and processed image.. lets leave it at that!! Anyone have details email me and I'll share with others.

As far as I am concerned.. they spoil and "damage" the stamp. There, that should provoke some debate... And on the subject of debate ( I do tee myself up don't I.. ) if you are interested in reading and moreso discussing Machins I do recommend you register and read http://allgreendownload.com/MachinForum/index.php this is Dave Arthurs Machin Forum.. I enjoy it.. a newbie forum in some ways so lets get it going..

Enjoy your stamps.. Michael