Anybody tried to add color to Rigid Resin?


After some phonecalls with the Formlabs Support, we were convinced that we would not run into any problems when combining the colors from the Formlabs color kit with Rigid Resin to do some color arrangement according to other components in our parts.

-> Poured 95 ml White color into Rigid, add some yellow, some magenta in miniscule amounts and voila… failed prints… :frowning:
The parts came off the build platform and I had to stop the print at like layer 15 or so. The prints stick to the LT resin tank firmly.

Anybody had luck with something similiar? Anybody tried to add color to some resin, which was not the “color kit” one?
I tried to print this with the rigid resin settings in PreForm, maybe another setting would have been better? Does the Rigid Resin setting or the Color Resin setting offer higher laser power?

Next thing I will try is to print far less objects at once on a freshly roughened build platform (grid 240 or less… lets see). Will keep this post updated and probably post some photos…

Wow - 95ml of white??? I normally add a maximum of 0.4% white pigment to any resin I use. White normally contains titanium dioxide which acts as a fantastic UV light blocker and makes printing much more difficult. As the tray takes 220ml resin to the full Line and the tank contains 1 L you seem to have in between 10 and 50% pigment. Its hardly surprising that its difficult to print and falls off the build platform.


I did not use pure pigment, I used the Formlabs Color Kit: You are supposed to add 100 ml or 10% of color resin (= mix between pigment plus resin) in total to your base resin:

Adding 10 ml (or 4 ml for that matter) of that color resin to 1 l of base (in my case rigid) resin has only a negligible effect. To much pigment can not be the root cause for the parts falling off the build platform.

But never the less, I think it may be a way forward to print with the color resin settings, as those are certainly for printing the “worst case scenario” of any self-mixed color resin - probably a mix of base resin plus 100 ml black or 100 ml white color resin.

I have trouble believing that formlabs would officially recommend to add the color additives to another resin, and would love to read the whole conversation to know how you arrived to a point where they would tell you it’s okay (although I understand this might not be possible for you to post that).

A 10% mix with another resin will undoubtedly change the ratio between each components of the resin mix, and thus its print settings. I suspect that the base resin for the color kit is unprintable or unreliable without adding the right amount from the color bottles, and that adding the recommended amount of “pigment” will balance the mix and make it print with Formlabs’ settings.

No, they would certainly not officially recommend that. Afaik I also did not write anything, which would suggest such.

The Formlabs support guy I had on the phone more or less told me that officially they will not support such trials (nobody expects that) and that we just “should / could try” if we were interested. Also he told us that we would change the specs of that base resin (yeah, well, thats clear, too) like temperature behaviour etc. So no official support, that is why I post this under “experimental”.

But other than telling me that this is not supported officially or that I used to much pigment … did anybody try something similar yet?

I guess I interpreted “we were convinced” as in “we were convinced by Formlabs”.

As for experimenting with colors, I have tried nylon dyes (Ryt DyeMore) to dye printed parts, which worked well although since there are no pigments in these products so transparency is not affected… you won’t get a solid red when dying a Clear part.
I used IPA in lieu of hot water to mix the dye and dip the parts. As the time I was using the 2-tanks manual cleaning stations so I was pre-rinsing the parts and then used the 2nd tank to dye.

Some have used the same dyes or the same type of dyes directly in the uncured resin. The quantities necessary to change the color are much much lower than 10% (you’d have to look on the forums and contact people to get proper metrics as I haven’t tried tried approach), and apparently results were good.

Now if your main issue is that the prints detached from the BP and stuck to the tank, maybe keeping the same Preform settings (Rigid profile) and raising the Z Offset value on the printer may help in increasing BP adhesion.

TY, John, for the informations. In the meantime I had another FL support phone call and the guy was pretty helpful, too:

  • Mixing color resin out of the color kit with other resins is not supported (still… totally fine) and will probably not work, as a) the printing parameters of rigid will not be correct anymore and b) you cannot easily use other printing parameters (you could still go into open mode - but you then only have a very limited set of possibilities)
  • What he and some colleagues tried is similar to your approach: Using acryl colour in small amounts in any base resin; not affecting the opaqueness of the resin;
  • He told me I could try highly concentrated pigments for acrylate based colours as an additive into the resin tank, again in small/miniscule amounts (again; not supported, not tried by Formlabs); dunno whether I gonna try that or not yet; I do not see this working as by changing the opaqueness I very probably will also change the printing parameters imho (UV-transparent pigments? Not that I would know of any…).

If I give it another try, I will post the results, but right now I am strongly leaning towards biting the bullet: Use the color base resin with the color kit and live with the worse material parameters.

BR, Peter

There is an alternative - A number of companies offer resin for the Form2 that have similar or better mechanical properties and printability to Formlabs own, they are ready optimised to a Form labs profile and are available almost to any RAL or NCS colour. If you use a third party cartridge then you enjoy all the functionality of the Form2. Alternatively “Open mode” is an option

Thank you, that is really good to know. Can you suggest any brand names? Would be very helpful!

I tried the pigments being sold by Spot-A materials, I was told their latest ones are not yet on their website but they sell them ready to use in a pre-loaded Syringe - they charge €10 (one colour) each one is enough to to do 1L of resin at 0.5%. They work very well. Probably worth seeing what you think. I got them to post me mine and bought six colours, so the cost of the shipping was sensible. Still have lots left after several litres of resin.

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That sounds great ! Are you able to post photos of the result with a “non dyed” part for comparison ?

TY, will give it a try when I got some time to spend again on this topic.