Publishing platform Substack is continuing to invest in video content as it launches the Substack Recording Studio , a built-in mechanism for creators to pre-record and publish videos. The studio, which is only available on the desktop, can support solo videos as well as conversations with up to two guests. Creators can add custom watermarks to their videos and share their screen with co-hosts. Once the recording is over, Substack auto-generates clips and thumbnails for sharing. “Until now, creating video on Substack meant  going live , or stitching together a separate stack of tools: a recording platform, a way to create and distribute clips, and something to design a thumbnail,” the company shared in a blog post . “Substack Studio brings all of those tools into one place.” The post also notes that creators who have used audio or video on Substack in the past 90 days have grown revenue 50% faster than creators who haven’t.…