MC3DPrint
FU is denominated by tier — a T5 spool stores T5 FU, a T1 spool stores T1 FU. One unit of Tier N FU is worth several units of Tier N-1 (the conversion ratio is set in config). Tier is value, not just capacity, and every spool T1–T8 holds a uniform 100,000 FU.
Where costs come from
Each block’s FU cost and tier are derived from its recipe graph — crafting, plus optionally smelting and stonecutting. A diamond block costs what its diamonds are worth; stone costs almost nothing. A block’s material tier sets the minimum machine and spool tier needed to print it.
Two different rules
These often trip people up, so keep them straight:
- Winding (making FU) is exact-tier — covered in Filament Units.
- Spending (printing) is down-only — a spool pays any cost at or below its tier, never above.
So a high-tier spool can print a whole stone house, but a T1 spool can never print netherite.
The markup
Lower-tier machines pay a higher FU multiplier per block, and printing always costs a little more than the matter is worth. Stack 4 Efficiency modules to reach exact break-even (1:1) — you can never print matter for less than it’s worth. See upgrades for module slots.
Printing food
Food has FU values too, so a printer in item mode can print meals — bread is cheap, cooked and golden food cost more. But food can’t be wound back into FU, so printing food is a one-way sink, not a loop.
Restricted trophies
Mob heads and skulls are trophy items: printers never duplicate them in item mode, and in blueprint mode they place only from an official curated blueprint that specifically carries them (like the Pig House’s decorative heads). A scanned or imported build containing a head prints everything else and silently skips the trophy — same anti-exploit gate as resins.
Heads still wind, though. Creeper, zombie, skeleton, and piglin heads recycle into Tier 4 Filament Units, so charged-creeper trophies aren’t a dead end. The wither skeleton skull is the exception: it winds for a Tier 4 payout but is wind-only — never printed, in any mode — so a wither-skeleton farm can’t mint printable wither-spawn ingredients.