Once you have your image file (JPEG or PNG), you can "attach" it directly to the .mkv file so it shows up as a thumbnail in Windows Explorer or macOS Finder:
: For a digital poster (one-sheet), the standard ratio is roughly 2:3 (e.g., 1000x1500 pixels). 2. Tools to Create or Retrieve Art Dolls (1987) PL.mkv
/Movies /Dolls (1987) Dolls (1987) PL.mkv poster.jpg (The main cover art) fanart.jpg (Background/landscape art) Use code with caution. Copied to clipboard How To Add Cover Art to Mp4 and MKV file Formats Once you have your image file (JPEG or