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# Create a collection

A collection is your own NFT contract. Every token you create belongs to one. Go to [`/create`](https://sepolia.modularium.art/create), open the collection dropdown, and choose **Create a Collection**.

## Fields

| Field | Notes |
| --- | --- |
| Collection Name | Required. Stored on-chain as the contract's `name`. |
| Slug | The collection's URL, `/collection/<slug>`. Filled in from the name until you edit it. 3–255 characters: `a-z`, `0-9`, `_`, `-`. Optional. |
| Collection Description | Optional. |
| Asset Type | **ERC-721** or **ERC-1155**. See [which type to pick](#erc-721-or-erc-1155). This can't be changed later. |
| Royalty Address | Who receives royalties. Defaults to your wallet. |
| Royalty % | Default royalty for every token in the collection. Defaults to 5%. |
| Collection Image | Uploaded to IPFS, 32MB max. |
| Banner Image | Wide image for the collection page header. |
| External Link | Optional link to your website. |

Click **CREATE COLLECTION** and sign one transaction. The factory deploys your contract and, if you set a slug, registers it in the same transaction. Once the deploy confirms, the new collection is selected and you can start [creating tokens](/create/tokens).

## ERC-721 or ERC-1155

| | ERC-721 | ERC-1155 |
| --- | --- | --- |
| Each token is | A 1/1, with one owner | An edition, with any number of copies |
| On create | Minted to you | You choose how many to mint to yourself, plus an optional max supply |
| Sell on create | List it on the marketplace | Open a public mint, with optional [requirements](/create/recipes) |

Pick ERC-721 for unique pieces and ERC-1155 for editions.

## Slugs

* Slugs are unique. The create form checks that your slug is free before deploying. If it's taken, choose another; nothing is deployed.
* Some slugs are reserved by Modularium.
* Collections without a slug are still reachable at `/collection/<contract address>`.
* You can add or change the slug later from the collection page. See [Manage](/create/manage#collection-settings).

## What you get

* **You are the contract owner.** Only you can change collection metadata and royalties, grant roles, or transfer ownership. Ownership transfer is two-step: the new owner has to accept.
* **Roles.** Your wallet starts with all three [roles](/create/manage#roles): Creator, Minter and Editor. You can grant them to collaborators.
* **Royalties are editable.** The default royalty isn't locked when the collection is deployed. You can change it later or lock it permanently.
* **Upgradeable, unless you renounce.** Collections are upgradeable proxies, and only the owner can upgrade one. Calling `renounceUpgrades()` freezes the contract code for good.