Exposure, lift and rest times

Before you start

You need a printer and a resin added in Settings (Your first print). Have your resin maker’s exposure and lift values for your printer to hand, and your printer’s manual. Every number below is a starting point for one printer and one resin: the maker’s values come first, and a small calibration print comes before a real one.

Find the fields

The same settings live in two places. In Settings, click your resin under your printer in the Machines list: the cards are “Exposure on the” and your printer’s name, “Waits”, and “Motion”. Edits save as you type and become the resin’s numbers for that printer.

In Preview, the “Print settings” section at the foot of the right-hand column shows the same fields under Exposure, Transition, Waiting and Motion, marked “this session”. Edits there change this session’s slices only; the resin profile keeps its own numbers. Picking another printer or resin puts them back.

Set the exposure

Layer height is in mm, and every other field in this section is in seconds unless noted. The Settings card has all of them; the Print settings section has Bottom layers, Exposure and Bottom exposure.

• “Exposure”: seconds each normal layer is lit.
• “Bottom exposure”: seconds each bottom layer is lit. It is much longer than the normal one, because it has to bond the print to the plate.
• “Bottom layers”: how many layers from the plate count as the bottom block.
• “Light power” and “Bottom power” (Settings only): UV power, 0 to 255, for normal and bottom layers.

The exposure belongs to the layer height it was measured at. Change Layer height and Encrust carries the normal exposure and any exposure band to the new height right away, turns the label to the warning colour, and says “Carried from” the old value. A button puts the old value back and keeps the new height. Editing the number yourself ends the carrying. The bottom exposure is never carried.

Encrust carries it along an exponential curve, not in proportion. With the assumed depth below, going from 0.05 to 0.025 mm keeps about 78% of the exposure, and from 0.1 to 0.05 mm about 61%, not half. The curve needs the resin’s light penetration depth, which no bundled resin states, so Encrust assumes 0.10 mm. That is an assumption, and the further you move from the height your resin’s maker measured, the less it can be trusted. Set the layer height first, then type the exposure the maker gives for that height.

Set the transition layers

Transition layers is a count of layers after the bottom block over which the exposure steps down in equal amounts from the bottom exposure to the normal one. The step is (bottom exposure minus exposure) divided by (transition layers plus one), and Encrust prints it as “Linear: each layer … s shorter than the one under it” in Settings, and as “Step between layers” in Print settings. With the generic Standard grey numbers (32 s bottom, 2.6 s normal, 8 transition layers) that is 3.27 s per layer. A count of 0 turns the ramp off.

To check the result, press Tab for Preview and drag the layer slider. The “This layer” heading reads “bottom block”, “transition” or “body”, and its Exposure row gives that layer’s seconds.

Set lift and retract

Lift is the distance in mm the plate rises after each layer, and Retract is how far it comes back down, normally the same. Lift speed, Retract speed, Bottom lift speed and Bottom retract speed are in mm/min. Bottom lift and Bottom lift speed apply to the bottom layers only.

Print settings shows Lift, Lift speed and Retract speed. Retract and the bottom motion fields are in Settings only. The file stores them per layer or in the header, depending on the format below, and the Anycubic container stores speeds in mm/s: Encrust converts.

Motion and waits cannot be banded by height. Only the exposure can.

Choose how the printer waits

The Waits card in Settings has two modes. Print settings has the same two as “Light off” and “Resting”.

• “Light-off delay”: seconds the printer waits before the light goes on for a layer. One field, “Light off”.
• “Rest times”: three waits around the peel, “Before lift”, “After lift” and “After retract”, each 0 to 60 s.

Only one mode is active. The one you don’t choose is written as zero. The waits count into the print time and into the file. Use the mode your resin maker’s values are given in.

Vary the exposure by height

Select “Layers and exposure” on the tool rail (key 7) and find “Exposure by height”. “Add band” adds a band that starts where the last one ends (at 0 for the first), is 10 mm tall and starts at the resin’s exposure. Each band, “Band 1”, “Band 2” and so on, has three fields:

• “From” and “To”, in mm above the plate.
• “Exposure”, in seconds.

A band covers every layer whose top lies from “From” up to, but not including, “To”, and its exposure replaces the resin’s. Bands may overlap, and the last one wins, so a narrow correction can sit over a wide band. The viewport tints each band’s height in the colour of its chip. The bottom block and the transition layers keep the resin’s own ramp whatever a band says.

A band is a height, not a layer count. Change the layer height and the same band covers different layers. Bands belong to the plate you are slicing, not to the resin: saving the resin does not save them.

Know which printers and formats take it

A band needs the printer to read per-layer values. In Settings, click the printer in the Machines list: the “Firmware” card has a “Per-layer settings” switch. “Open printer settings” in the Layers panel jumps there. When it is off, the printer ramps the bottom block itself from the header’s numbers and Encrust never asks it to read the per-layer tables. The Layers panel then says “This printer reads the header alone, so exposure cannot vary by height” and offers “Open printer settings” instead of “Add band”. A custom printer starts with it on, and the bundled Saturn 4 Ultra profile has it off. Turn it off if your printer’s maker says it ignores per-layer values, and test on an empty plate first.

The format matters too:

Format	Per-layer exposure	Per-layer motion and waits
.goo	yes	yes
.ctb	yes	yes
.cbddlp, .photon	yes	no
Anycubic Photon Workshop (.pwmx and others)	yes	lift distance and speed only
.cxdlp	yes	yes
.zip of gcode, .cws	yes	yes
.sl1, .sl1s	no, and refused	none in the file

A .sl1 or .sl1s archive holds one exposure and one layer height for the whole stack, and no lift, retract or light-off values at all: those tilting-vat printers own their motion. If your job has an exposure band, Encrust refuses to write the file rather than write it flat. The bottom block and a transition ramp (numFade) are the only things that vary there.

If something goes wrong

“Add band” is missing

The printer’s “Per-layer settings” switch is off, and the Layers panel says the printer reads the header alone. See the section above before you turn it on.

Slice is greyed out and names exposure by height

A band is set and the printer’s “Per-layer settings” switch is off, for instance after you switched printers. Remove the band, or turn the switch on if you have tested that your machine reads per-layer values.

The exposure changed when you changed the layer height

That is the carrying. Look for the warning-coloured label and the “Carried from” line; the back button restores the value you typed.

Settings you edited in Print settings are gone

They apply to this session only. Put them in the resin’s card in Settings to keep them.