Why Clear resin is the "best" - the most versatile Standard Material

Why Clear Resin?
Having tested all of Formlabs’ common resins the clear resin doesn’t only seem to be the one producing the nicest surface it is also the most versatile for any project. Simple mechanical parts, like engines and interior or architectural models with lots of glass and windows. Certain animals like Insects with clear wings, and microscopic aquatic life-forms. And anything else one can possibly think of.
There are 3 problems attached to formlabs’ clear resin - it is never truly glass clear - no matter the post production effort - it has a yellow tint. The most critical aspect however is it being quite brittle. Depending on the type of model and detail it will have to be handled like walking with 4 raw eggs in each hand.
Here is an example that shows why clear resin is the king of resins if one was to show the true capabilities of the Form2 (the strong and flexible resins should be made into clear, if at all possible).
The first image shows many of the different parts that I had the machine make in order to build the actual model. For this particular model the machine produced over 35 parts (including tests and re-dos). Most at 50 Microns and some at 25 Microns. For a model like this 100 microns is simply not fine enough.
I went through 2+ Liters of resin and 3 tanks.

Here is an in-between step image:

The next image shows the Machine next to the Model for scale purposes.

Here are some close ups:



she looks a little worried.

How are you transferring the load for such a dramatic cantilever? I sure hope there’s something internal that can help carry that weight across.
I would be interested to hear if you have had any issues with cracking or warping of the resin parts over time when cantilevered like this.

Clear has been my favorite universal resin, with its balance of properties (speed, strength, lower abuse to the tank). To me it is stronger than the Grey, which I now tend to favor because its F2 has the new tank (just received my second LT tank, but trying to decide whether to try dental clear yet, instead of hand-making on 3D printed models. I believe that the yellowing occurs because of the curing initiators for the longer wavelengths of light, but there are also components to influence other properties (how fast or extensive cross-linking occurs, etc.). It is certainly a tough balance that FL has to strike, especially at their favorable price point.

This is wonderful… in a disturbing kind of way.

Awesome job ! :+1:

Hi Jens,

The clear resin is great! Have you tried avoiding post-curing the clear resin? This should leave it less brittle and more clear. You can then use methods mentioned here to keep it clear when exposed to UV light.


Hi Trevor,
I personally never post cure. Completely unnecessary with all of Formlabs’ basic resins.

Sanding certain parts are nearly impossible depending on their surface detail and detail size, especially fine ridges, spikes, scales and tips next to each other.
That’s why we see a very simple part like a lens as an example in the link.

I use clear lacquer to bring back the clarity and shiny surface. Also if keeping a display model in constant UV light it should be coated with a UV protection coat (not all clear coats contain UV inhibitors!) or it eventually will yellow over time, which is not what I am referring to when saying it has a yellow tint - and possibly crack depending on the thickness and severity of exposure (for it to crack it would have to be in direct sunlight for a long time and undergo numerous temperature changes).

Dipping is also something not particularly good for larger parts and highly detailed parts as the coat can create sagging, pooling and runs when not thin enough or drying too quickly - then we’re back sanding…again that’s why Formlabs always uses most simple parts for any type of demos. Post production effort is usually far more than what meets the eye that’s why a 3D machine is nothing more than a tool and with the Form 2 we do have a pretty good tool, considering.

And yes the Clear is the best :slight_smile:

Thanks very much for liking the model.