PRINTED portfolio?! You ask.
Yessir. I again traveled to the ice cold city of New York, New York on February of this year(2017) for the annual SCBWI(society of children's book writers and illustrators) conference. I was there, in person, in the flesh with no computer to hide behind. This meant as well that my work had to be mobile, agile, hostile...sorry, got carried away.
I don't have an iPad and the last thing I wanted was to show people my work on my tiny iPhone screen. PLUS I love print. Most of us maybe are illustrating for print, books, magazines etc. It's all the more helpful for your viewer to see and handle your physical artwork. So I made a full sized portfolio, inserted printed pages into my Pina Zangaro. I also wanted to have a small booklet portfolio to give away to friends, art directors and editors.
To do this you've got to know Adobe InDesign (check some tutorials online) or have a really close friend that does. Also helpful to know something about basic graphic design, the spacing and layout of your images and text. When in doubt keep everything really simple, no flourishes and frills, just the facts ma'am. Let your art be the focal point and not have to fight with background paper color or filigree typefaces.
While assembling this portfolio keep in mind what your best work is, but also who your audience will be. For me it was the children's literary world. I included work that featured fun characters in interesting situations.
Where to print might be your biggest trouble. If you have a college or university near you that has a dedicated printing and bookmaking facility (resource for teachers and students, as well as the public sometimes) I would suggest trying that. They usually have very low cost and aren't in a business mindset like Fedex Office or something like that. It's a slower pace and if you can establish a nice relationship with the people in charge it will only help you out.
For added effect I ordered clear, plastic sleeves for my small portfolio. To me it felt more like a cool gift, like a mint condition comic or something. I also inserted business cards into each of them, knowing they wouldn't fall out because of the sleeve.
If you've never printed any of your work before I definitely suggest trying it on a small scale. It will get you to start thinking about clarity in your work. Images can look very different on a backlit computer screen than in print. It takes a few adjustments for me every time to get similar values on the printed page. Good luck!