The square 4-panel flyer
A square 4-panel flyer closes to a square cover and opens into four panels — as an accordion strip, or as a quarter-fold that unfolds in two directions.
ClosedSquare, 1:1
Panels4
FoldAccordion or quarter
FilesLayered PSD, smart objects
The quarter-fold is the more interesting of the two. Instead of opening into a long band, it unfolds up and across into a big square sheet — a small square cover that becomes a poster-sized square when it's fully open. That makes it a nice trick for something that hands over compact and then reveals a large image, a map, a menu or a two-sided story, while still closing to that tidy considered square.
The accordion version behaves more like the strip formats — four panels zigzagging open, read panel by panel, good for a sequence. Either way you're planning how the piece reveals itself: the quarter-fold has an inside-and-out logic like a greetings card, so the reading order isn't a straight line and it's worth roughing out which panel faces up at each step before you design.
In the sets: folded, part-open and laid flat from above, so you can present the square cover and the full open sheet together. Each is a layered PSD with smart objects — the artwork sits on its own layer, so replacing it leaves the fold, lighting and shadow untouched.