Although you can have an online portfolio, a graphic designer who does print work still needs a physical portfolio. The way I have produced a portfolio has changed a lot of the years and the size of my portfolio has shrunk from A1 straight out of college (which was a nightmare to carry round) to the A3 size it is now.
My earlier portfolios all contained printed work which was painstakingly spray mounted onto black mount board or card and laid out in a way to try and display my work to its full potential. Heather at www.heatherink.blogspot.com has a great tutorial if you are looking to create a portfolio using this method.
My next portfolios went much more digital and I would create eps my brochures (from quark) and pull them into photoshop on an A3 page. I would then take elements of the brochure that I was showing such as logos etc and use them as faded watermarks/shapes in the background in effect creating a design of the entire A3 page with the design work as the focal point.
My later portfolio pages of graphic design work including the one I have now are much simpler. I create pdfs in quark of my brochure (or other design project) pages then pull them back into A3 Quark documents with my logo at the top of the page. I put simple keylines around the work and hope that the design work speaks for itself without the need for further embellishment. I also make all the work of the same orientation to save keep turning the portfolio round when talking through the work. I put the pages in plastic sleeves and put them in an A3 black ringbinder portfolio. As the work is often reduced in size to fit on the A3 pages I tuck a few finished print examples of a few pieces of work in the pocket at the back of the portfolio.
How do you display your work in your portfolio?