Photo slates, dark spots

[Terrijhill]

Hi all,

I wonder if anyone can help? I am fairly new to sublimation, but haven't run into too may problems as yet so this is throwing me! Ive started sublimating slate, and originally the coasters I started off with came out perfectly. But a week or so later, while trying to move on to larger slates, and also while going back to the coasters I'm getting these dark spots over the image.

Epson eco tank
Inkforinkjets ink
s race paper

Ive tried a combination of temperatures, times, face up, face down, image taped, image placed, blow out paper, pre drying the print on the press, pre heating the slate etc and every time I get these spots.
I then when back to the aluminium sheets, and they are perfect! not a spot in sight. So I'm not sure if the printer is to blame. I am desperate not to give up, but its getting close to that time now. Very frustrating. I would be ever so grateful for any advice, Thank you in advanced :redface:

Attached is a particularly bad one! (my nephew) Some are much less obvious, but obvious to me none the less.

Many thanks
Terri

[Mrteajunkie]

That to me looks like the coating isn’t thick enough on the slate!
Have you pressed them for too long or too high a temp and it’s lifting the coating.

[Terrijhill]

Thank you for your reply Mrteajunkie!

Initially I wanted to blame the slate/coating, but having bought from 2 different wholesalers I'm pretty sure I'm the problem!

There are no signs of the coat lifting, that I can see... I have been working around the 200 temp, for 480. But have also increased and decreased that so see if it makes a difference, and unfortunately I can't see that it has.

[JMugs]

I haven't done slates for a long time but my notes show
Preheat slate for 1 minute,
Then 210 degrees for 8 minutes.

I always used a silicon sheet over the top to smooth out any irregularities in the slate and allow even pressure all over.

That would have been sawgrass ink, trupix classic paper, ricoh SG3110DN,

Janners

[Terrijhill]

Thank you for your reply, I really appreciate you taking the time to refer to your notes :biggrin:
I have ordered a silicone sheet so hopefully that'll fix it! thank you again