What affects 3D printing cost — the big factors, ranked

Ranked by how much it moves the price

Most of the variance in 3D printing cost for a given model comes from a handful of levers. Here they are, roughly ordered by how much they change the final number on a typical functional or decorative part.

1. Print time (machine hours)
2. Material type and density
3. Infill percentage and wall count
4. Support material
5. Post-processing and labor
6. Setup fee and markup

1. Print time

On almost every part, the machine's hourly rate ends up costing more than the plastic. A 5-hour print at a $5/hour machine rate is $25 of machine time, regardless of whether the part is 20 g or 200 g of filament.

Print time is driven by layer height, nozzle width, print speed, and — critically — the tallness of the part. Two parts that weigh the same but one is thin-and-tall will take far longer than a squat one. If you need to cut cost:

• Increase layer height (0.2 mm → 0.3 mm shortens print time ~30%).
• Orient the part so its tallest axis is shortest.
• Reduce infill (see below).
• Group multiple parts in one print to amortize setup.

2. Material type and density

Different filaments have different densities and different prices per gram. For the same printed volume, the weight (and therefore material cost) varies:

• PLA — 1.24 g/cm³, cheapest per gram, fine indoors
• PETG — 1.27 g/cm³, slight premium, better heat and moisture resistance
• ABS — 1.05 g/cm³, lightest per volume, needs enclosure
• TPU — 1.20 g/cm³, flexible, more expensive and slower to print
• Nylon, carbon-fibre-filled, wood-filled, etc. — all cost more per gram
• Resin — usually sold per litre, roughly 2–5× the per-gram cost of PLA

On a small 20 g part, jumping from PLA to a fibre-filled filament might add $1–$3 of material. On a 500 g part, the same jump can add $25+. The savings from picking cheaper material scale with size.

3. Infill and wall count

Infill is the internal fill density — 100% is fully solid, 0% is hollow. Most FDM parts use 15–30% infill, because the outer walls provide almost all of the strength you need.

Going from 20% to 60% infill doesn't double the cost, but it does increase both material and print time noticeably — roughly 25–35% more on both. For purely decorative parts, dropping to 10% infill with three walls saves significantly without changing how the part looks.

Wall count is the perimeter loops. Two walls is the minimum most slicers use; structural parts often bump to three or four. Each extra wall adds material roughly proportional to the surface area of the part — a small effect on small parts, a bigger one on large ones.

4. Support material

Any overhang past 45° or so needs support — scaffolding that gets printed alongside the part and thrown away. Supports add:

• Extra material (5–25% of the part's volume, sometimes more)
• Extra print time (similar range)
• Extra labor to remove them cleanly
• Risk of leaving marks on the support-facing surface

Orienting the part thoughtfully at the slicer stage is free savings. If you're getting a quote, asking “can this part be reoriented to avoid supports?” is often the biggest cost lever available.

5. Post-processing and labor

Support removal, sanding, priming, painting, assembly, and packaging all take human time. A print that costs $3 in plastic and $10 of machine time can easily add $20 of labor if it needs sanding smooth, priming, and painting in multiple colours.

Most shops bill this at an hourly rate, but for simple finishing it's often rolled into a per-part fee. The biggest savings come from accepting a rougher finish — layer lines are fine for many functional parts and some aesthetic ones.

6. Setup fee and markup

Every print, no matter how small, has a few fixed costs: slicing, loading the file, prepping the bed, inspecting the first layer, and removing the part afterwards. That's usually 5–15 minutes of human time per job.

On a $2 part, the setup fee dominates; on a $200 part, you never notice it. That's why nearly every printing service has a minimum order price — it's the setup fee made explicit.

Markup covers failed prints, shipping supplies, payment-processor fees, platform cuts, and the shop's actual margin. 30–60% on top of cost-of-goods is typical; it's not padding, it's the cost of actually running a business.

What to actually do

• If you're buying a print: ask about layer height, infill, and whether supports are required — those are the three biggest cost levers available to the shop.
• If you're pricing a print: calculate material cost, machine-time cost, and labor cost separately, then apply a flat markup. Don't try to roll it into a single price per gram — two parts can weigh the same and cost very different amounts to produce.
• If you're comparing quotes: make sure every quote uses the same material, infill, and finish. “3D printed” is not one thing — the quality and method behind the same nominal part can vary 3–5× in both price and quality.