How long should a pre-print check take?

About a minute once it becomes habit. That is the whole point: sixty seconds of checking prevents the six-hour failed prints, wasted resin, and vat cleanups that come from skipping it. The cost of running the list is trivial compared to the cost of a failed plate.

Why do my prints fail even when the settings look right?

The most common hidden causes are a damaged or loose FEP film, a build plate that lost its level or was not tightened down, and exposure settings that belong to a different resin than the one currently in the vat. All three pass a casual glance, and all three are on this checklist for exactly that reason.

Do I really need to watch the first layers print?

Yes. The first ten to twenty layers are where the raft either grabs the plate or fails. If you catch a bad first layer in the first few minutes you can cancel, fix it, and lose almost nothing. Walk away too early and you find out hours later with a cloudy vat and an empty plate.

What temperature does resin need to print well?

Most standard MSLA resins want roughly 20 to 25C. Below that they thicken and under-cure, which shows up as failed supports and incomplete layers that look like a settings problem. In a cold room, warm the bottle, heat the space, or raise exposure to compensate.

Why strain resin that is already sitting in the vat?

Past prints leave small cured flakes and partial failed layers floating in the resin. If one sits under the build plate at the wrong moment it can puncture or scar the FEP and ruin both the film and the print. Straining when you reuse vat resin removes them before they cause damage.

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Resin Printer Pre-Print Checklist: 9 Things to Check Before Every Miniature Print

A 60-second pre-flight checklist that prevents the six-hour failed prints. The nine things I check on the Saturn before every miniature print, and why each one matters.

This guide contains affiliate links, and I may earn a small commission at no extra cost to you.

A failed resin print almost never tells you it is failing. The screen says printing, the timer counts down, and you walk away. Six hours later you come back to a clean build plate, a cloudy vat full of half-cured garbage, and a FEP film you now have to inspect and probably strain. The print did not fail at hour five. It failed in the first two minutes, on something you could have caught before you hit start.

That is what this checklist is for. Nine things, about a minute to run, and it eliminates the large majority of avoidable failures. None of this is glamorous. It is the unsexy pre-flight routine that separates people who print reliably from people who post “why does my printer hate me” threads every weekend. If you are brand new to all of this, read the complete beginner’s guide to resin printing miniatures first for the full workflow, then come back and pin this. And before any print session, gloves go on and ventilation comes on, which is covered properly in the resin printing safety guide.

The 60-Second Version

Here is the whole checklist in one block. Screenshot it, print it, tape it to the wall next to the printer. The explanations below cover why each one matters and what goes wrong when you skip it.

#	Check	Failure it prevents
1	Resin level vs. job volume	Print runs the vat dry, tops of models missing
2	Resin stirred and at temperature	Under-cure, failed supports, soft prints
3	FEP film and vat inspected	Silent peel failures, punctured film
4	Build plate clean, level, locked	Raft never adheres, whole plate fails
5	Sliced file: zero islands, supports, tilt	Mid-print collapse, detached parts
6	Exposure matches the resin in the vat	Wrong-resin under or over-exposure
7	Right file, right printer, on the drive	Garbled print or no print at all
8	Gloves, ventilation, vat seated, area clear	Spills, exposure, mechanical crashes
9	Watch the first layers	Catch a failure while it costs nothing

1. Check the Resin Level Against the Job

Before anything else, look at the slicer’s estimated resin volume for the job, then look at the vat. They have to agree.

This bites people printing a full plate. A single 28mm miniature uses a few milliliters. A full plate of terrain or a batch of twenty heroes can use 60 to 100ml or more, and a low vat does not have it. When the resin drops below the level the plate is pulling from, the top of every model just stops printing. You get a plate of legless soldiers and a confused expression.

For anything bigger than a handful of minis, keep the vat at least a third full and comfortably above the minimum fill line printed on most vats. If you are not sure how much a job needs, slice it first and read the resin estimate the slicer gives you, then make sure the vat actually holds that much before you start.

2. Stir the Resin and Check the Temperature

Resin pigment settles. Grey resins are the worst for it, and they are also the most popular for miniatures because they prime so cleanly. If the bottle or vat has sat for more than a day, the pigment and the photoinitiator are no longer evenly distributed, and an unstirred print cures unevenly.

Stir the vat gently with a plastic spatula before every session. Do not whip air into it. If you are pouring fresh from the bottle, shake the bottle hard for thirty seconds first.

Temperature is the other half of this check, and it is the one cold-garage printers miss. Most standard MSLA resins want to be around 20 to 25C. Below that they thicken, flow slowly back under the plate between layers, and under-cure. The symptoms look exactly like a settings problem: failed supports, missing layers, prints that feel rubbery. In winter, warm the bottle in a tub of warm water, heat the room, or bump exposure to compensate.

One more thing while you have a spatula in hand: if you are reusing resin already in the vat from a previous session, pour it through a fine paint strainer first. Old prints leave cured flakes behind, and those flakes are FEP killers.

3. Inspect the FEP Film and the Vat

This is the check that prevents the failures that make no sense. The FEP (or nFEP) film is the clear membrane at the bottom of the vat that the print peels off of on every single layer. It takes abuse, and when it is compromised it causes failures that look like everything except what they are.

Look across the film at a low angle under good light. You are checking for:

Cloudiness or fogging from accumulated micro-scratches, which scatters light and weakens cure
A permanent dimple or stretched spot where a print once stuck and pulled the film, which becomes a recurring failure point
Scratches or punctures from spatulas and cured debris
Slack tension so the film flexes too much on peel

A loose or damaged FEP is the single most common silent cause of a dead plate. If the film looks tired, replace it before the print, not after it ruins one. The FEP film replacement guide for Elegoo and Anycubic printers walks through it step by step.

While you are looking in the vat, sweep for any floating cured bits. A flake of old resin sitting on the film when the plate comes down can puncture it. Strain the resin (step 2) if you see debris.

4. Clean the Plate, Confirm Level, Lock It Down

The build plate is the foundation. If the raft does not weld to it, nothing else matters.

Wipe the plate face with 99% IPA and a paper towel, and scrape off any cured nub left from a previous removal. A single hardened bump throws off the first layer across the whole plate. For the IPA itself, a gallon of 99% lasts a long time and is cheaper by volume than the pharmacy bottles.

Then confirm the level. You do not need to re-level before every print, but you do need to re-level any time the plate has been removed, knocked, or crashed since the last successful job. If your last print failed and you yanked the plate to clean it, re-level now.

Finally, and people forget this constantly: tighten the plate lock screw all the way. A plate that is even slightly loose shifts a fraction of a millimeter during the first peel cycles, and the raft never gets a clean grip. The print either falls off the plate or prints with a warped base.

5. Re-Open the Sliced File and Read It

Open the sliced file in the slicer preview before you export it. Not the raw STL, the sliced and supported file, because the failures you are hunting for only show up after slicing.

Run through four things:

Island count is zero. In Lychee the count is right there in the support view. In ChituBox, scroll the layer preview for red-flagged islands. An island is a chunk of model floating with nothing supporting it from below, and it will detach and crash into the FEP. Zero is the only acceptable number.
Supports on every thin extremity. Sword tips, staffs, antennae, outstretched fingers. Auto-supports miss these constantly.
Orientation is tilted. The model should sit at an angle, not flat on its back or bolt upright. If you are unsure why, the supports guide covers orientation and placement together because they are the same problem.
The raft is present and the model is actually attached to it.

For the slicer-level settings behind all of this, the Lychee slicer settings guide and the ChituBox settings guide have the per-field detail.

6. Match Exposure to the Resin in the Vat

This is the failure that gets experienced printers, not beginners. You print one resin happily for weeks, swap to a different bottle for a special project, forget to load the matching profile, and the whole plate comes out under-cured or fused into a brick.

Every resin has its own exposure window. A fast Elegoo standard grey and a tough Siraya Tech ABS-like resin are not interchangeable on the same settings. Before you slice, confirm the profile loaded matches the resin physically sitting in the vat right now:

Normal layer exposure
Bottom layer exposure
Bottom layer count
Lift speed and lift distance

The moment to be paranoid about this is right after any resin change. If you switched colors or brands since the last print, assume the profile is wrong until you have checked it.

7. Confirm the File, the Printer, and the Drive

A small one that wastes a whole evening when it goes wrong. Three quick confirmations:

The file is sliced for this exact printer. A file sliced for a Saturn 4 Ultra will not print correctly on a Mars, and the resolutions and plate sizes do not match. The slicer ties the output to a machine profile, so make sure it is the right one.
The format is right for the machine. The correct file type for your printer (the .ctb, .goo, or equivalent your machine reads) needs to be the thing you exported.
It actually copied to the USB drive, and the drive is seated fully in the printer. “Copied” sometimes means “still copying” when you pull the drive too soon, and a half-written file is a dead print.

8. Gear Up and Clear the Deck

Now the physical setup, in the thirty seconds before you press start:

Gloves on before you touch resin or the vat. Uncured resin is a skin sensitizer every time, not just on the day you react to it. A box of nitrile gloves by the printer means you never skip this.
Ventilation running. Window cracked, fan exhausting outward.
Vat seated and screws tight. A vat that is not locked down can shift or leak.
Nothing in the plate’s travel path. The plate drops to the vat floor, so anything resting on top of the printer or wedged near the gantry gets crushed.
Paper towels staged for the inevitable drips when you pull the plate later.

If your bench is missing any of the basics here, the resin printer accessories guide is the full stocked-kit list rather than item-by-item links.

9. Watch the First Layers

The last item costs you about two minutes and saves more failed prints than any other check on this list. Do not walk away at “start.” Stay until the raft and the first object layers are down.

The first ten to twenty layers are the entire failure window for adhesion. This is where the raft either grabs the plate or it does not, where a loose plate reveals itself, and where a missed FEP problem shows up as a print that never appears. Watch the plate dip into the vat, hold for the long bottom exposure, and lift cleanly. Watch for the raft taking shape on the plate as it rises.

If something is wrong, you see it now, while canceling costs you a few milliliters of resin and a quick wipe. Walk away at the wrong moment and the same problem costs you six hours and a vat cleanup. This is the difference between catching a failure and discovering one.

What I Run Through on the Saturn

In practice this is not a ceremony. On my Elegoo Saturn the whole thing takes under a minute and most of it is reflex by now. I lift the lid, glance at the resin level and give the vat a slow stir, look across the FEP for cloudiness or floaters, and confirm the plate screw is tight from the last time I pulled it.

Then it is the file: I re-open the sliced preview, check the island count is zero, and confirm the profile name matches whatever resin is loaded, because switching between my standard grey and a tougher resin for gaming pieces is exactly where I have burned a plate before. Drive in, fan on, lid down, start.

And I stay for the raft. Every time. I have lost enough early-layer prints by trusting the first two minutes that watching them is no longer optional for me. Once the base is down and the first object layers are lifting clean, I will leave it. Before that, I am within arm’s reach of the cancel button.

When You Skip It

You will skip it eventually. Everyone does, usually when they are in a hurry or printing “just one quick thing.” The quick thing is precisely when it goes wrong, because the rush is what makes you forget the plate screw or the resin swap.

When a print does fail, the print failures troubleshooting guide walks the symptoms back to causes. But the honest truth is that most of what lands people in that guide is a checklist item they did not run. Sixty seconds up front is cheaper than the diagnosis afterward.

Print the table at the top. Tape it to the wall. Run it every time.