Getting resin exposure right is the single biggest factor in MSLA print success. This tool gives a sensible starting point for both normal layers and the all-important bottom layers, scaled to your layer height and printer’s LED power, so your first exposure test lands close.
How it works
Curing resin is an energy problem: each layer needs a certain UV dose, and exposure time is that dose divided by the LED’s power.
exposure = base × (layer_height / 0.05) × (reference_power / LED_power)- Layer height sets the cure depth required, so time scales with it.
- LED power divides the time — a brighter array cures the same layer faster.
- The base resin value captures how reactive each resin chemistry is (flexible and tough resins are slower than standard model resin).
Because real printers and resin batches vary, the tool reports a roughly ±25% window around the point estimate. You then print a calibration matrix and pick the value that gives crisp detail without bloating.
Bottom layers are handled separately. They are exposed many times longer (the multiplier) to weld the print to the plate, then transition layers fade that long time down to the normal time over several layers to avoid a hard seam.
Tips and notes
- Always validate with a printed exposure test (a stepped wedge or a calibration model such as a validation matrix) rather than trusting any single number.
- Colder resin cures slower — warm the resin and room to around 25 °C for consistent results.
- If supports tear off the plate, increase base-layer count or base exposure before touching normal-layer time.
- If small holes close up or text fills in, you are over-exposing the normal layers; reduce the time in small steps.