Initially, the renders were in PNG format. However, one of the developers suggested using the webp format instead, as it has a smaller file size without compromising on quality. Moving forward, I'll only use webp. The compression quality in webp is almost negligible, so there's virtually no difference between the original PNG and webp. Sometimes, I need to re-render scenes if there's an error or some issues during the Photoshop processing of the render. In these cases, I might end up keeping a few renders in PNG format.