Brochure printing without the extra 1/2 inch of space at the top and bottom

I’m trying to print a brochure with 2 pages per 8x11.5 sheet. I have a front cover printed set to borderless printing, and on 1 page per sheet it prints fine, but whenever I print it in brochure mode the cover is condensed to where there is a 1/2 inch of extra space at the top and bottom of the page, but not the sides. Is there a way to get that 1/2 inch removed?

Use a paper format where putting two pages on one actually fits without any excess whitespace.

The DIN sizes are designed that way, the height/width ratio is so that you can always exactly fit two smaller pages with the same aspect ratio onto one larger one. This isn’t possible with letter size.

letter is 215.9 mm × 279.4 mm - to make it fit without added whitespace, the shrunk page must be 215.9 mm tall. That would be a ratio of 279.4/215.9 = 1.294117647, thus it would have to be 215.9/1.294117647 = 166.831818182 wide - but 166,8*2 = 333,6 - that is much wider than the available 279.4 - thus the limiting factor is the width of the two shrunk pages.

279.4/2 = 148.7 thus the pages have to be shrunk with a factor of 215.9/148.7 = 1.451916611 thus the resulting height is 279.4/1.451916611 = 192,435294118, leaving 215.9-192.4 = 23,5 whitespace - your 0.9 inch in total, or approx. 1/2 inch on top/bottom.