for printed portfolio, try not print smaller the 10"x12" or 10"x15".
you need to mount the prints on high quality mounting board, usually will give two inches borders, the mounting board will be around 16"x20".
if you opt for a window matt, you can go for glossy finishing.
as such, a twenty pieces of portfolio will cost a few hundreds dollars to produce, and it weight close to 10kg. and you also need a very presentable portfolio case too, that's how nowadays hardly people want to have a portfolio in hardcopy.