Is publishing in an Open Access journal the only way to do Open Access?

No.

Publishing in a (pay-to-publish or free-to-publish) Open Access journal constitutes the Gold Road towards Open Access. Open Access works published via the Gold Road are immediately openly accessible and are usually protected by an open licence, such as Creative Commons .

However, there is an alternative way to publish in Open Access, namely the Green Road. The Green Road refers to the parallel publication of a version of the manuscript in an open repository, or self-archiving. Open repositories can be institutional, as our own SERVAL, or disciplinary. The publication is often delayed (embargo period) and allowed only for the author accepted manuscript (AAM), also known as postprint. This is the manuscript accepted for publication (post peer-reviewed), but before all copyediting by the editor. There are no costs for researchers to follow this road.

Below you can find a scheme that shows the available roads to Open Access.