Polymer is the item that marks the end of the stone age. It costs 2 obsidian per craft, unlocks at level 48 alongside the Fabricator, weighs 0.25, and stacks to 100. The numbers are small; the consequences are not. Every recipe above metal tier assumes you have a polymer supply, and the two ways to get it — crafting and harvesting organic — behave nothing alike.
The figures here come from the cached fields in ark-resources.json and ark-items.json.
The two polymers are not interchangeable in practice
| Property | Polymer | Organic Polymer |
|---|---|---|
| Weight | 0.25 | 0.25 |
| Stack size | 100 | 20 |
| Weight of a full stack | 25 | 5 |
| Spoils in | never | 1,800 seconds |
| Health effect | none | -500 |
| Level | 48 | not listed |
| Engram points | 6 | not listed |
| Made at | Fabricator, Tek Replicator | harvested from creatures |
| Added in | — | — |
Polymer is a strong, light material in ARK that you shape and heat-treat into casings used across many crafting recipes. — ARK Wiki
The crafted version never spoils and stacks five times larger. The organic version gives you 5 weight per stack, a 30-minute timer, and a health penalty if you misclick it in your inventory. That is not a balanced trade — it is a design signal that organic polymer is meant to be spent immediately, on site, not carried home.
The recipe and what it really costs
Polymer’s recipe fields list quantity1: 2 against Obsidian, with a second ingredient slot also set to 2 units. Obsidian weighs 1.0 and stacks to 100, so the input is heavier than the output by a factor of eight:
| Input | Weight in | Output | Weight out |
|---|---|---|---|
| 2 Obsidian | 2.0 | 1 Polymer | 0.25 |
| 200 Obsidian | 200 | 100 Polymer | 25 |
| 2,000 Obsidian | 2,000 | 1,000 Polymer | 250 |
Crafting polymer compresses weight 8x. That is the entire reason the recipe exists: obsidian is a heavy cave resource, polymer is a light fabricator resource, and the Fabricator is the machine that performs the conversion.
Which means the practical bottleneck is obsidian, not the craft. The obsidian page covers where it comes from; the short version is that caves and mountains are the only sources and both are contested.
Where polymer goes
The cached recipes show a resource that appears in almost every advanced item, usually in quantities that dwarf its own craft cost:
| Recipe | Polymer | Other inputs | Level | Points |
|---|---|---|---|---|
| Cryopod | 8 | 10 Crystal, 15 Fiber, 5 Hide, 2 Ingot, 4 Oil | 51 | 20 |
| Ghillie Chestpiece | 6 organic | 10 Hide, 4 Fiber | 33 | 11 |
| Ghillie Leggings | 8 organic | 12 Hide, 5 Fiber | 33 | 11 |
| Compound Bow | 95 | 85 Metal Ingot, 75 Paste | 79 | 40 |
| Chemistry Bench | 250 | 250 Ingot, 250 Paste, 100 Sparkpowder, 250 Crystal, 250 Electronics | not listed | 65 |
Two things follow. First, ghillie is the only major recipe that prefers organic polymer — 6 to 8 units per piece, which is a single creature’s worth and spoils long after the armour is built. Second, the Chemistry Bench at 250 polymer is 125 crafts and 250 obsidian, which is the real gate between “I have a Fabricator” and “I have a production base”.
The Cryopod at 8 polymer is the small, high-value end: one cryopod is a fifth of a stack, and losing a stack of cryopods to a full inventory is a worse afternoon than losing the polymer.
Organic polymer: the field material with a timer
Organic Polymer spoils in 1,800 seconds — thirty minutes — and stacks to 20. Compare that with raw meat conventions and the design intent is obvious: it is a perishable.
| Quantity | Stacks | Weight | Time before it is worthless |
|---|---|---|---|
| 20 | 1 | 5 | 30 minutes |
| 100 | 5 | 25 | 30 minutes |
| 200 | 10 | 50 | 30 minutes |
Stacking more does not extend the timer; it just means more of it dies at once. The correct pattern is to harvest organic polymer only when a recipe is already waiting, then craft immediately. If you are farming it for later, you are farming compost.
There is one structural exception worth knowing: Corrupted Nodule weighs 0.25, stacks to 20 and spoils in 1,800 seconds, and appears in recipe slots as an alternative to polymer. On Extinction, that makes corrupted creatures a polymer-equivalent source with exactly the same spoilage discipline required.
A polymer plan that does not stall
The arithmetic suggests a simple sequence:
- Obsidian first. 100 polymer is 200 obsidian. Do not start the craft until the obsidian is banked, because the Fabricator will otherwise sit idle waiting on cave runs.
- Craft in batches of 100. One stack of polymer is 25 weight and covers eight cryopods or a ghillie set with change.
- Never bank organic. Use it on ghillie and on anything already queued, and let the rest spoil rather than fill slots.
- Count the bench. A Chemistry Bench at 250 polymer is the single largest polymer sink in the cached data, and it is worth building before the forge.
These four rules are the difference between polymer as a constant chore and polymer as a background process. The resources strategy page applies the same batching logic to the rest of the set.
The chain below and above
Polymer sits on top of two chains. Below it: obsidian from caves, and paste from chitin. Above it: the Fabricator-tier recipes that assume you have both. The cementing paste page covers the second input, and the crafting guide shows how the stations stack.
If you are prioritising what to farm next, the resources tier list places polymer in context, and the items guide lists the finished gear it feeds.