This Shapeways tutorial explains how to avoid 3d printing errors that occur due to the minimum wall thickness requirements of 3d printers.

Minimum wall thickness is defined as the minimum thickness that your model should have at any one given point.

In the case of the image above d=1 is the minimum thickness.

If you are designing a cylinder for example the cylinder itself should at all times have a larger diameter than 2mm. If you would turn that cylinder into a straw the edge of that straw should at all times be at least 2mm thick.

The minimum wall thickness depends on the material you choose. If you always want to be in the clear we recommend sticking to 2mm.

Here you can see the wall thickness of one of our Light Poems.

If you do not have experience with designing for 3D printing, minimum wall thickness is an often encountered error. In the virtual world of a rendering your model can have any dimension or be as thick or thin as you want. If you would like to make a model in the real world though, for 3D printing, there are some constraints though.

Even though you could use a minimum wall thickness of 1mm when using White, Strong & Flexible we recommend that you stick to 2mm. We would also never recommend making large portions of your model this thin because this would make it excessively delicate.
For an example let us look at the lovely Chameleon by R3PO.

For scale I put it behind a white board marker. Here you can see that the model is quite detailed.  Actually the model is so detailed that some of the finer detail such as the pupils in the eyes do not show up with my lens.


 

This model should always be at least 2mm. Indeed as we see here the tiny looking legs are 2mm in diameter.

The tongue itself is one mm in diameter at the thinnest point.

In this case a 1mm wall thickness works but we would never recommend that you make large portions of your model 1mm thick. You must also remember that the tongue itself is very fragile.

Getting your model just right will become much more complicated initially if the walls of the model are approaching the limit of 1mm. You might inadvertently cause a hole in your mesh for example. Or  more commonly, make one part just a tad bit too thin which causes it to not be able to be 3D printed.

If you absolutely positively have to use a 1mm wall thickness, such as in the Chameleon model above, then go ahead.  But, we would never recommend that you make large portions of your model 1mm thick. This would lead it to be impossibly fragile and this might make the model so weak that we couldn't even get the support material out without breaking it, let alone ship it to you. Excessive thinness could also lead to errors in the final build.

Look at these pictures of Christel's Impractical Half Bowl. This beautiful model was ruined by the printer because it was simply too thin. The wall thickness was 1mm, so just as thick as the Chameleon tongue. But, because in this case the 1mm area was not a tiny detail but made up a large proportion of the surface of the bowl and the 3D printer was unable to print it properly.

This is a side front of the model, so far so good.

But if you look at the model from the side you can clearly see, towards the rim of the bowl in the center, where the printer had trouble with printing the bowl.

Here you can see that the models surface is 1mm nearly all the way round.

And a top view shows you the printer error.

You should be able to measure the thickness of your mesh using the 3D software that you use.