How to Remove Support Marks from Resin Miniatures Before Painting
Clean support nubs, pock marks, and scars off resin miniatures before primer. Tools, timing, and the fill technique that hides the damage for good.
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Every resin print comes off the plate with a set of small scars where the supports touched the model. How bad they are depends on support density, contact depth, and how the model was oriented — but they’re always there, and if you prime over them without dealing with them first, you end up with a miniature that has visible bumps, nubs, or craters under the paint.
This guide is about making support marks disappear before primer goes down. It’s the step between cutting supports off and starting to paint, and it’s the one most new hobbyists skip or do badly.
If you haven’t gotten to the support-cutting stage yet, the supports guide covers placement and removal technique. This guide picks up after the supports are off and you’re looking at the marks they left behind.
What Support Marks Actually Are
There are three distinct problems you’re fixing, and they need different treatments.
Contact nubs. Small raised points where a support column met the model surface. These are the most common kind and look like tiny bumps, usually 0.3–0.6mm across. A light fingernail drag can feel them before your eye can see them.
Flat scars. When a wider support base met a thin surface, you get a flat scraped-looking area instead of a round bump. Common on cloak undersides, the bottoms of shields, and the inside of raised arms.
Pock marks. Deeper craters left by heavy contact points, or by suction damage where a large flat surface pulled too hard against the FEP. These are the worst kind because sanding can’t fix them — they need filling.
The treatment sequence is the same in every case: remove the bulk of the mark mechanically, smooth what’s left, fill anything still visible, then check your work under primer.
Timing: Do It in the Right Order
There’s a specific sequence that makes this whole job easier and a wrong order that makes it harder.
The correct order:
- Wash the print in IPA (or water, for water-washable resin)
- Cut supports off while the print is still in its green state
- Final UV cure
- Knife-pare remaining stubs
- Sand scars smooth
- Fill pock marks
- Prime and inspect
The mistake most beginners make is cutting supports off after curing. Post-cure resin is hard and brittle — supports snap at the contact point, but they also sometimes take a chunk of model with them. Cutting in the green state prevents that.
The opposite mistake is trying to sand or knife-work the model in the green state. Uncured resin is too soft to knife cleanly and smears when sanded. Cure fully, then do the surface work.
Tools You Need
A small, specific toolkit handles every support-mark scenario on miniatures.
Fine flush-cutters. Not standard electrical flush-cutters — the type with a thinner, sharper blade that gets into tight spots. Xuron Micro-Shears and Tamiya Sharp Pointed Side Cutters are the two brands most miniature painters settle on.
A sharp hobby knife. Tamiya and X-Acto both make good ones. Keep a supply of fresh blades. A dull blade catches and tears resin instead of slicing cleanly through a stub. Swap blades more often than you think you need to — a fresh blade is the difference between a clean cut and a chewed surface.
Fine needle files. A six- or ten-piece set of fine-grit needle files handles the scars flush-cutters leave behind. Flat, half-round, and round shapes cover most situations. A cheap hobby set is fine here — you’re not doing precision metalwork, just taking a nub down flat.
Sanding sticks or fine sandpaper. 400–800 grit sanding sticks smooth flat areas faster than files. For very fine work, 1000 grit and higher. Foam-backed sanding sticks are easier to control than loose sandpaper on a small model.
Liquid Green Stuff. Citadel’s Liquid Green Stuff is the standard for filling small pock marks on printed minis. It brushes on, wipes with a damp brush, and cures in an hour. A single pot lasts a long time because you’re applying it a drop at a time.
Green Stuff or Milliput. For larger voids, two-part epoxy putty. Kneadatite (the green/yellow strip sold as “Green Stuff”) is the standard, but Milliput is cheaper and works for gap-filling where detail isn’t critical. You’ll use this far less often than Liquid Green Stuff on a printed mini.
That’s the whole kit. Total investment is under fifty dollars and the consumables last through dozens of models.
Technique by Mark Type
Small contact nubs
Hold the model steady. Lay the flat of a hobby knife blade parallel to the surface so the cutting edge sits right against the nub. Push the blade across the nub with light pressure — don’t stab down into it, slice across it.
The nub shears off clean. What’s left is usually a flat scar that a few passes with a fine needle file or a 600-grit sanding stick blends into the surrounding surface.
Work across the feature, not into it. Always rotate the model so you’re cutting away from detail you want to keep — the next surface your blade meets after the nub should be something you don’t mind marking.
Flat scars from wide support bases
These are the easiest to fix because the starting surface is already roughly flat. Run a flat needle file or sanding stick across the scar until it blends into the surrounding surface.
If the scar is in a recessed area — inside the folds of a cloak, under a raised arm — use a half-round file or a rolled piece of sandpaper wrapped around a toothpick to reach in. Patience matters more than force. A dozen light strokes beats three heavy ones.
Pock marks and deep craters
This is where Liquid Green Stuff earns its place in the kit.
Take a small detail brush. Load it lightly with Liquid Green Stuff. Dab the material into the crater — don’t brush it across, dab it in. Let it bulge slightly above the surrounding surface. Rinse the brush, then with the damp (not wet) brush, wipe the excess flat against the surrounding surface. The water dissolves the top of the putty and lets you feather it into the existing surface.
Let it cure for an hour minimum. When dry, it’s hard enough to sand. Take a fine sanding stick and blend the cured fill into the surrounding area.
For really deep craters — 1mm or more — use two-part Green Stuff or Milliput instead. Mix a small amount, press it into the void, and shape with a dental pick or sculpting tool. Two-part putties take hours to cure but hold their shape during sanding better than Liquid Green Stuff.
The Primer Check
Primer is the test. It evens out surface color, which reveals every remaining scar, nub, and pit under a uniform layer of grey or black paint. Things you couldn’t see on bare resin become obvious.
Spray a light primer coat. Let it dry. Inspect under a bright lamp from multiple angles — overhead light hides flat scars but catches raised bumps, side lighting catches both but especially the scars.
Anything you find now gets a second round of the same treatment. A raised bump? Knife and sand. A pit you missed? Liquid Green Stuff. Once the second fix is cured, spot-prime that area only — no need to re-prime the whole model.
Two rounds of inspect-and-fix is normal for a first-time printer. One round is achievable with practice. Zero rounds means you’re not looking hard enough.
The primer comparison covers which specific primers work on resin without obscuring detail, if you haven’t picked one yet.
Common Mistakes
Trying to remove supports in one chunk. People grab the support raft and try to lever it off the model like pulling a Band-Aid. This cracks the resin at the contact points and leaves chunks of model stuck to the supports. Cut each column individually.
Sanding too early. In the green state, sandpaper smears uncured resin and clogs immediately. Cure fully before any abrasive work.
Sanding near fine detail. A flat sanding stick hitting a face, a belt buckle, or scale armor destroys the detail in two seconds. Use a knife for cleanup in detail areas, and reserve sanding for large flat planes like shields, bases, and cloak backs.
Skipping the fill step. A shallow crater looks like it’ll disappear under primer. It won’t. Deep enough to catch your fingernail is deep enough to see through six coats of paint.
Filling with too much Liquid Green Stuff. Over-filling and then trying to sand it flush removes surrounding detail. Aim for a fill that sits slightly proud of the surface and wipe the excess with a damp brush before it cures.
Once the support marks are gone and the primer coat is clean, you’re at the starting line for the actual painting work. The painting guide for 3D printed resin miniatures picks up from there with shading, highlighting, and basing.
Before any session of knife-work, filing, or priming at the bench, review the resin printing safety guide — sanding dust from cured resin still benefits from a mask and good ventilation, and solvents in some primers need the same treatment.