I tried searching for this here and in support, but what are the recommended sizes or aspect ratios for blog graphics? Specifically, the ‘Post main image’ and the ‘Post thumbnail?"
Bryon, I know I answered your question about blog image sizes on the Facebook Group, but just to clarify for anyone reading this, the table posted above might be mis-leading. That is not telling us to make our images that size. It is just letting us know what widths the editor assigns for various iterations of the uploaded images.
Blog "settings" for each article includes 2 images. "Main" and "Thumbnail".
The Main image renders depending on how (or IF) you are using it in your blog article template. The "thumbnail" image is used as the thumbnail in the All Posts Widget. But more importantly, it also gets used as the OG image for social sharing. As such, best practice is to make it an aspect ratio equal to (and no bibber than) 1200 x 630 px. Minimum size is 600 x 315 (I like 800 x 420, but that's just me).
It will still work if you use a different size. But best practice is those dimensions. But hey, I am OCD about that stuff :-)
This support article may be of help:
Thank you, this is helpful for the thumbs. Do you know if the Post main image is used for OpenGraph purposes?
As mentioned above by @Sheyla you should use 300px for the blog post thumbnail. For the social (open graph) it's kind of wonkey really. Sometimes the image looks AMAZING and other times it doesn't. For Social open graph images we use 1200x630px.
Thank you @Bruce_McCaughan for your OCD awesomeness.
For anyone reading that, OG is not 'original gangster' graphic, but 'open graph'.
Who says Opengraph isn't an OG 😜