A part that comes off a 3D printer is rarely the object you had in mind. The shape is there, the detail too, but the surface still carries the marks of the process: fine stacked layers, the uniform color of the filament, sometimes a small mark where a support held the part. Nothing abnormal — that's the raw state. The question is what you want to do with it next. At PrintWonders, a 3D creation workshop in Vatimont, Moselle, France, finishing is a stage in its own right, done by hand. Here's what it really changes.
Why a raw part doesn't look like a finished object
FDM printing, the layer-by-layer deposition of molten filament, builds your object the way you'd stack very thin sheets. Each layer leaves a visible line on the sides of the part. On a technical enclosure or a functional bracket, nobody notices them. On a figurine, a decorative object or a gift, the eye sees them immediately, especially in raking light.
Then there's color. A print comes out in the shade of the filament used: uniform, flat, without nuance. A model sculpted with dozens of details therefore comes out in a single color, which flattens exactly the detail you wanted to show. Finishing exists to answer those two points: texture and color.
Sanding and priming: the work nobody sees
It all starts with sanding. The surface is worked with abrasive paper, progressively, to soften the layer lines and smooth the areas where print supports — those temporary props printed under overhanging sections — have been removed. It's long, it's repetitive, and it's what separates a properly painted part from a painted part that still visibly looks printed.
Then comes primer, an undercoat applied before color. It has two roles: evening out the surface so paint grips the same way everywhere, and revealing the remaining defects. A primed part turns monochrome and matte, and at that point the imperfections you couldn't see on colored plastic jump out. We correct, sand again if needed, and only then paint.
That's the paradox of finishing: the most decisive stage is the one you'll never see on the final object.
Hand painting: what's at stake at this stage
Hand painting is the moment the part stops being a print and becomes an object. You work in thin coats, let them dry, come back. Volumes gain depth, details emerge, a texture can be suggested where the model had none.
This work is also what gives each piece its character. Two copies of the same file painted by hand will never be strictly identical, and that's precisely what we're after. It's the same hand that paints the objects in our store, from deck boxes to ambient lighting, and it's what earns us 4.9/5 across more than 300 reviews.
A useful point of vocabulary when describing your project: talk about use rather than technique. A figurine destined for a display cabinet, a prototype to show in a meeting and an object handled daily don't call for the same level of finishing. Describe the scene, and we'll translate.
Matte, satin or gloss varnish: a choice that changes how the object reads
Varnish is the final coat, the one that seals the painting work. Beyond that role, it completely shapes how the piece is perceived, and choosing between the three finishes is anything but trivial.
- Matte: no shine at all, light doesn't bounce. It's the finish that best brings out volumes and sculpted detail, ideal for figurines, models and cosplay props.
- Satin: a soft reflection, halfway between. The most versatile for an everyday object or a gift, it gives a surface that's pleasant to both eye and hand without looking plasticky.
- Gloss: a strong reflection, a lacquered look. It attracts light and works well on pieces with simple geometry or decorative objects meant to be seen from a distance.
If you're hesitating, describe where the object will end up: on a lit shelf, in a hand, on a desk. The finish follows from the destination.
When finishing is worth it, and when raw is enough
Finishing isn't compulsory, and we're the first to say so when it adds nothing. A shim, a cable holder, a spare part hidden inside an appliance: the raw part does the job, and the budget stays on what matters.
Conversely, finishing is fully justified as soon as the object is seen, given or displayed: figurines, decor, cosplay accessories, promotional objects, pieces destined for a client presentation. That's what we detail in our article on 3D printing for cosplay.
One last scenario: very fine pieces, where the level of detail matters more than added finishing. There, the question shifts to the process itself, and our resin printing service often takes over.
FAQ
Does finishing lengthen lead times?
Production is still stated as 3 to 5 working days depending on the complexity of the part and the workshop's load, with finishing included in that calculation. The quote spells out what's planned before you approve anything.
Can I choose my colors precisely?
Describe what you have in mind when requesting the quote, with a reference image if you have one. We'll tell you what's achievable on your part before starting production.
Can I order a raw part and paint it myself?
Of course, many of our customers do. You can also ask for sanding and priming only: the part arrives ready to paint, and you keep the creative part.
Want to see your piece finished by hand?
Send your STL, OBJ or 3MF file through our on-demand 3D printing page, specifying the finish you want, and receive a free quote within 24 hours. Prefer to size up your project first? The workshop page walks you through it. And to discover what happens between printing and dispatch, our article on behind the scenes at the workshop opens the door.