Ghost marks with new tank and 1 print


I’m having a major problem with ghost marks in my tank. I received my Form1+ about a month ago and have gone through several tanks which now all have clouding. This while i’ve only used up to 300ml’s per tank with different resins.

I opened a support ticket because my print with black resin failed completely and it turned out to be dirty mirrors. Melinda from the support team was a great help and told me exactly how to clean each mirror. Apart from that she sent me a coupon for a new tank because my black resin tank was full of very clear ghost marks as well as a dent which came into the pdms layer because of the last failed print.

This is what the tank looked liked after 300ml of black resin and the failed print: You can clearly see the ghost marks, and I’ve circled the dent as well.

Yesterday I received my new tank and I still had a project which I needed printing in black resin. So I unpacked the resin tank, inspected it to be sure it was clean. Used some novus1 and a pec-pad to wipe the tray underneath to make sure it was ultra clean.

I ran a print which was 180ml’s and this print came out perfect.

When I wanted to start a different print and I used my scraper to mix the resin in the tank, I noticed vague ghost marks again! I tried to gently scrape the scraper over the pdms layer to see if the marks could be removed as is written on the support page ( This unfortunately didn’t help. I cleaned the tray with novus1 underneath again, as a last hope. but obviously that didn’t make any difference.

Anyway… to summarize: I have printed 1 single print with a brand new resin tray and used 180ml’s of resin and already the tray is full of ghost marks… Formlabs state that a tray is good for about 1L-2L’s of resin, however, these are the state of my tanks:

  1. Black resin tank, used approx 300ml. Clouding all over the place, and there’s a black spot (3mm diameter) which has probably ruined the silicone layer completely, as it seems to be a hole/dent where the resin sticks.

  2. NEW black resin tank. used 180ml’s. Clouding forming already, all over the PDMS layer as the print nearly covered the whole build area.

  3. White resin tank, used approx 400ml. Clouding visible.

  4. Clear resin tank, used approx 700ml. Clouding is visible

  5. Grey resin tank. used approx 200ml. No clouding visible. YAY!

Here’s a photo of the brand new resin tray with clouding:

What should I do with this?

Of course there are ways to replace the PDMS layer yourself… But technically this would mean that for 1L of resin. I have to buy +/- 4 tanks… Which is €200,-…

Very thorough write-up! I’m curious, what layer thickness did you use for this black print?

It’s important to note that ghosting can be a sign of tank failure, but in some cases prints come out just fine with some ghost marks. I’d be interested to see what happens when you print again on this almost-new black tank.

Personally, black resin is my favorite resin to use. It captures the most detail and in my experience results in the fewest failures. Black resin also requires the highest exposure power. You may notice that on bulky 100 micron prints, black prints can take up to 10% longer than clear or grey prints. This higher exposure may cause more wear on the tank, but again, as black resin has more R&D behind it than our other general purpose resins, it’s designed to last longer with tanks.

In sum, give another print a try. Ghost marks may indicate issues, but that’s not always the case.

Hi Craig,

I prrinted it at 0.1mm.
I just finished anther print, It was a smaller print, but I placed it at the same angle as the last print. Luckily it printed perfectly, so I guess you’re right that in some cases prints come out just fine, even with ghost marks on the tank.

I guess it’s a trial-and-error thing, whether ghost marks become an issue for printing. Obviously the first photo I posted represent an unuasable tank as the ghost markings actually cast a shadow! For the other tanks I shall try and print some more and see if they affect the prints as well.

Thanks for your reply Craig!