SLA - Theory

https://www.3dhubs.com/knowledge-base/introduction-sla-3d-printing Links to an external site.

One of the more interesting aspects of the SLA process is the support structure. Because of the Formlabs process of inverted SLA, all of the parts are built hanging from the support structure. Therefore, the support structure is much more significant. Combined with the limited number of print parameters (layer height is one of the few), the importance of the support structure is magnified. The following webinar from FormLabs does a good job explaining it. Watch from about minute 20 to minute 39 of the webinar. 

https://3d.formlabs.com/understanding-sla-3d-printing/ Links to an external site.