When you’re watching an epic movie filled with sweeping cinematography, you probably want the highest on-screen resolution possible with, say, a Blu-ray disc or high-definition stream. But if your children are watching old Disney movies in the playroom while arguing with each other over Legos, a standard picture from a classic DVD will probably suffice. The point: Don’t overpay for something that isn’t really necessary.
The same thought can be applied during 3D printing when you’re prototyping with stereolithography (SL). Proto Labs uses three resolutions that range in cosmetics and functionality. Normal resolution (NR) provides the lowest cost, but lacks fine detail. With NR you get a layer thickness of 0.004 in. with a minimum feature size of 0.010 in. — but that might be all you need in early prototyping.
If your part requires an elevated level of precision, there’s high resolution (HR). Here, you get a layer thickness (0.002 in.) and minimum feature size (0.004 in.) half of NR. It costs more, but the boosting the part quality may be well worth it depending on your intended application.
You can even step up to a higher level of precision, which most manufacturers are unable to provide. Micro resolution (MR) — the Blu-ray of additive resolutions, if you will — can provide optimal part detail on the smallest of part features. With MR, you get a layer thickness of 0.001 in. and minimum feature size of 0.002 in. Yes, that is an actual life-sized ant (not an evil oversized ant) atop a microscopic chess board. You can even see the staircase inside the rook!