It is about blocking UV, too. Black is fairly light resistant and so does not really need UV blockers, whereas the colors have more sensitivity to it.
Depending on the exact ink formulation, particular brands may put more UV inhibitors in different colors. In your Canon, apparently Magenta has more UV inhibitors.
I've read of others having even more luck with 6 color CcMmYK printers, using light colored green prints because it uses the photo inks to print it, and the photo inks have a lot of UV inhibitors due to their increased sensitivity to fading.
Steve Greenfield AE7HD
--- In Homebrew_PCBs@yahoogroups.com, "alex4459jopiklal44" <christiansen_alex@...> wrote:
>
>
> try with red ..
> I had the same with a cannon. that claimed 2400 ..but they all have a smaller resolution in black when you read the specs. and they often have a lower resolution in the other direction.. that means, as I see it ,that it is the lowest resolution that count.. so I printet a B/W with my new cannon.. looked like yours.. but then with red it was better than my old HP 710. I can see it when it is etched.. the edges is much sharper. and red gives perfect stop from the UV.. yellow and blue did not stop as well.
> alex
> my printer is the cannon IP4850 and I print on transparancy and use precoated boards , expose with uv in 3 minutes .I can do 5 mil traces and clearance, at least over 5x2cm without any fault.
>
> >
> > just make my first test on the Xerox solid ink printer
> > (collor-cube 8570n)
> >
> > that was shame , noting close to 2400dip claimed by xerox
> > this was same pcb image print wit dell laser printer (600DPI)
> > and whit the Xerox for comparaison (transparency over white sheet)..
> >
>