Flyers
We define Flyers as any printed item smaller than A4. A typical Flyer is an A4 sheet folded to 1/3rd A4. This is a very economical size for printing. A4 folded to A5 is also another useful format
But if budgets allow we can print any size or shape, once you move out of a rectangle shape (4 edges that can be trimmed by a guillotine) you need a cutting form and then the only limitation is our creative invention
Postcards are another great idea.