The booklets are not stapled. The printer cannot do this. Only the division on the pages is done with the help of the booklet printing function. Since the printer can only print A4, the maximum size of the booklet will also be A4. In other words, the individual pages will be reduced to A5 (2 A5 next to each other equals A4 brochure). I do not know whether it is possible to print an A5 brochure.