Blog Post

Demystifying 3D Printing Resolution, Accuracy, and Precision

We’ve heard the term resolution applied to a number of things and more commonly in the world of digital photography and printing. This is a term that is also widely used within the 3D printing industry but can be easily misunderstood or misconstrued.

It can sometimes be difficult to visualize the difference that print resolution makes, or what we even mean by resolution, but when evaluating 3D printing technology, understanding this is extremely important. Different applications require different technical requirements, and of course, there is also the economics to consider.

Microscope images of glaucoma stents, printed at different resolutions with various 3D printing technologies

Pictured above is a micro 3D printed glaucoma stent, a medical device that is inserted into the eye as a treatment protocol for glaucoma. This part is traditionally machined in production, which is very expensive.

A desktop SLA machine will give you about 50µm resolution as you can see on the far right. An industrial SLA system will give 30µm resolution. With the BMF process, you can get down to resolution that will be appropriate for this part and will be printed “true to CAD.”

Accuracy vs Precision

Not only is there confusion about what high-resolution 3d printing really means, but there can also be misconceptions about what accuracy and precision are. Accuracy is generally described as the closeness of a measurement to the true value. Precision would be defined as the ability to achieve repeatability and/or reproducibility of the measurement. The image above depicts visual ways to interpret the difference between accuracy and precision.

We recently printed a test part on the microArch S240 using BMF’s RG resin and then compared this same part printed with a third-party resin specifically developed to print small parts with ultra-fine features on a competing SLA platform.

Part Features: Hole arrays of 50, 100, 200, and 300 um​, Varying pillar designs (solid & hollowed out)​, Open channels varying widths​, Wall thicknesses ranging from 10-220 microns​

The first comparison we did was using 50µm holes. You can see in the image below that the RG Resin on microArch S240 has all the holes built through, all sizes, and spacing within 25 microns. With the other test part, printed in a competing material/system the 50µm holes did not print at all. 

50µm holes printed on the microArch S240 system in RG
50µm holes using alternative micro feature material and SLA system

When comparing the performance on printing open channels, using RG Resin on microArch S240 all channels resolved, all measured within +/- 25µm tolerance.

On the test part using a competing material and system, the smallest printed channel (60 microns) would not resolve, many others printed undersized by ~80µm.

Test channels printed using RG resin on microArch S240
Test channels printed using competing material/printer

When it comes to 3D Printing, resolution, accuracy and precision are three very important terms that are often used interchangeably. At BMF, these are the cornerstones of our value proposition. We offer the most accurate, precise, and high-resolution micro 3D printers on the market.

Capable of achieving resolution of 2µm~50µm and tolerance of +/- 10µm~25µm, BMF’s PµSL technology provides mold-free, ultra-high-resolution fast prototyping and end part capability. If you’d like to have a test part printed, please don’t hesitate to reach out.