The veil is always an open crypto currency. In most crypto currencies, privacy is an option only in the user's wallet, meaning that the user can spend anonymously or in a more private way.
Technically speaking, the niqab project, like other Zeroco-focused projects, has two types of coins: bazcoins and zerocoins. In most other projects, users must manually fill their bazoco with zerocoins, if they choose. With napkin, bazcoins are automatically placed in Zerocoins above 10 bazcoins. In other words, when a user has at least 10 bascoines, it is automatically dipped into the zero-mine. The reason for the existence of two coins and the fact that each coin is not printed on Zero is because they are the same currency (veil), because they have an affordable cost of printing and spending on zero currency. Please note that an average user doesn't have to worry about eventually seeing a balance
In veil, bascoin operations are made anonymous using RingCT and secret addresses. RingCT is a method of making the sender's digital signature anonymous by combining the sender's digital signature with random other signatures from the block chain's history, creating a final, unique signature. Then, using a range proof, the amount of transactions is hidden. Eventually, the network does not recognize the sender or the amount in a transaction, but by using an encryption key image, miners can verify that the transaction is valid and that there is no double expense.