I'm not a subeta newbie, I've been here for 5 years, but I'm new to the whole Pet profile creation thing and I'm starting by creating the art for a couple of my pets. So for a custom overlay, What is a good size image to make? Or the required if I'm simply just missing where it say the required size? While I'm asking, how big should I make the background? I'm sorry if these are dumb questions, I just cant seem to find the answers.

Found on the Custom Overlays page (you actually have to click Upload New to find that!) (:

Thank you so much!

as said, 200x200 is the official pet image size, but you can always put a bigger version on your pet profiles if you want with the following code:

{background:url(URL); width:XXXpx; height:YYYpx} as for backgrounds, it's usually best to keep it within the dimensions of 1200x700 pixels, so users with smaller screens can still see everything. most people usually have a 'main' background image that fits within those dimensions, and then a repeating background pattern behind it that fills the rest of the page if someone's browser window is bigger. that way you don't have weird empty white space, but you also don't have the profile spilling off the edge of the screen.