When you mint you NFT collection, the project policy will be locked shortly afterwards.

Policy locking is a good thing - it locks the collection and lets buyers and owners of your NFTs know that no further changes will be made to the collection.

Just-in-time minting is a process where NFTs are only minted at the time of purchase..

For some cryptocurrencies where the cost of transactions (known as "gas") is incredibly high, just-in-time minting can be a way to avoid paying transaction fees until required.

The downside to just-in-time minting is that the policy remains open (for years or even indefinitely) to allow new tokens to be minted at any time. This leaves owners and buyers uncertain about what new tokens may be added to the collection in the future.

Cardano does not suffer from high transaction fees (see proof-of-stake vs proof-of-work) and so just-in-time minting is not required. Wytchspace offers cheap minting for your NFT collection with auto policy lock that gives your buyers the confidence to know that the collection they are buying from is complete and will not be modified in the future.