Five: What are the EXACT DIMENSIONS for an ideal banner?

Within Squarespace, they recommend that your images be at least 1500px wide in order to retain the best quality of your image when uploading it to the banner.

With that said, exact dimensions aren't always the answer here as Squarespace's templates are responsive, and all Banners will experience some cropping depending upon the screen size you view your site on.

However, when asked for exact dimensions, they do recommend 1500px by 1000px as a good rule of thumb.

Additionally, they have a couple of guides you can review when it comes to formatting your images for your Squarespace Site. The first is their Image Format guide here:

http://help.squarespace.com/guides/how-should-i-format-my-images-for-display-on-the-web

As well as their guide here on how to specifically format images for Banner Areas on your site:

https://support.squarespace.com/hc/en-us/articles/223016508-Formatting-background-and-banner-images-for-responsive-design

There is already a thread on this, with an answer by the template developerhttp://answers.squarespace.com/questions/26029/why-does-squarespace-resize-my-banner-image

I found the site width, changed my banner image size to match and unchecked the stretch image (Brilliant to have those things in Completely different places btw!). My banner image is still way too big! No one will write, "The optimum width and height is X," because it implies that Squarespace is limited.

Thanks for your help, scoobie. This doesn't seem to answer the question though; especially as it pertains to the asker's specific website and it appears that site is no longer relevant.

Are there more recent and/or less situation-specific responses put there?

He says make it the width of your site and switch off stretch. Isn't that the answer?

Hey bro!interesting question, i dont even know, cause i using a good software which includes standarts of size, such as Ronyasoft Poster designer, here the link for u,bro link text