Summary: This paper, which is a work in progress, explores the limits for participation in open, commons-based cultural production. By an ethnographic exploration of two cases – a Siberia-driven experiment to create a feature animation film of industry quality called ‘Morevna project’, and an Amsterdam-driven similarly ambitious projects with the code name ‘Gooseberry’ the paper discusses the tensions arising in their attempts to reconcile openness, quality and Internet mediated collaboration in their production process. As a consequence of these tensions, the paper argues that technologies and approaches considered as enablers of broader participation by media scholarship – open source technology; volunterism; and Internet mediated collaboration, can for certain media forms – such as open-source animation film – act as thresholds for participation. The paper ultimately argues that certain media forms are easier to produce collaboratively – and therefore participatory – than others and points to the shortcomings of existing theories on user driven Internet-mediated cultural production arguing the need for their tighter adjustment to the specifics of different media forms.