Mug Printing Issue

[Justin]

I've just come up against a new problem. I'm printing a mug with a solid black background. It looks OK until you look at the side opposite the handle, there's a patch there that looks more brownish, almost as though the black is thinner (if that makes sense!)
Obvious thought was that it wasn't cooking long enough but everything else has been fine and press has just had a new blanket.
Very difficult to photograph, especially with my lack of camera tallent! I wonder if it could be pressure related? Just hoping it's not linked to the inks/printer.
Appreciate your advice.

This pic kind of enhances the problem with the flash on:


This is a bit nearer actual colouring:

[bms]

Hi Justin,

We come across issues like this with the Ricoh printers and the new Subli-JetR inks. There is nothing wrong, just that the inks are more likely to brown and blur when they have too much heat for too long a time. We went through many test prints thinking we had to increase time/ temperature/ pressure to get the browns to go black, but the problem was resolved by going the other way! In a nutshell, if you over cook the mugs then the image starts to blur and a brown hue forms. Try taking your temp down by 10-15 degrees and cook for just 3 mins from start to finish. What temp/ time are you pressing for at the moment?

[Justin]

Thanks Martin. At the moment I'm printing 195c for 210 secs. I'll drop to 180 secs and see what happens.

Cheers,
Justin

[Justin]

I dropped the time to 180 secs and this improved the black considerably. Lowered temp to 185c and black now looks fine. The image has started ghosting at the bottom edge, the old flame type effect coming from the bottom, have to work on that now!

Cheers,
Justin

[joconnell]

Martin,
Thanks very much for your advice. I was having the same problem and being new to this game you wonder what you are doing wrong. I now am using 185C and 180 seconds and it has cured the problem.
Many thanks again.
James

[bms]

Cool - glad to hear the advice works!