#Ask Steemit: What size graphic do you need to have a perfect thumbnail?

Hey Steemit! I have noticed several posts where the thumbnail picture is either too small or too large.

This post is a perfect example!

I was wondering if any one knows what size/dimension graphic you need to use to have a perfect thumbnail on Steemit?

Please let me know in the comments!

If you have any other formatting tips drop those here too!

Thanks!