The Finch report (see Nature 486, 439; 2012) on ways to achieve universal open access to scientific papers favours a 'gold' approach that involves a publication charge for authors. This must not stand in the way of 'green' self-archiving of open-access journal articles (see

Research institutions and funders need to mandate green open-access self-archiving of the final, refereed versions of all journal articles as soon as they are accepted for publication.

Paying for gold open access pre-emptively today, without funders or institutes having first mandated green open access, will delay universal access and waste scarce resources. The money to pay for gold open-access publishing will become available once green open access has eventually made subscriptions unsustainable.