This is part two of our four part series Part 1: Specifying the correct figure dimension in {knitr}. Part 2: What image format should you use for graphics (this post). Part 3: Including external graphics in your document. Part 4: Setting default {knitr} options. There are (at least) three file formats to choose from: JPEG, PNG and SVG. Attribute JPEG PNG SVG Type Raster Raster Vector Transparency No Yes Yes Animation No No Yes Lossy Yes No Yes Recommended Occasionally Yes Often If you are reading this via a syndication site, be sure to go the original post for updated links.