The first Eclipse book was SABRE by Don McGregor and Paul Gulacy, in 1978, among the very first graphic novels. 40 pages in black and white, with this wraparound cover.
There was also a 2nd printing (the version I first got), a 10th anniversary printing (1988), a 20th anniversary printing (1998), and a 30th anniversary printing.
https://comiconlinefree.com/sabre-1998/issue-Full

In addition, it was reprinted as the first two issues of the SABRE comic series. Which I like best because it presented the issues in color, and in a comic book size.

When I want to see it in black and white, I like the 20th anniversary edition best.

The initial SABRE graphic novel, along with the initial releases for 4 years, presented stand-alone works in a magazine-size book format, that in both size and as stand-alone works set them apart from pretty much everything else being published.

They didn't start doing comics till 1982.