In my Portfolio,
I use *plenty* of examples of my design work,
done for past employers.
I think you're safe as long as you credit the Project team in full.
If I co-designed a project,
I always credit the other Designers, Project Manager(s), Interior Designers,
Engineers, etc.
and always list who the Architect/Engineer of Record is.
This is to be sure that you are not misrepresenting yourself,
and letting your prospective employer know exactly the role you played on
each project.
If your protfolio is geared mainly toward showing that you were a
draftsperson on some nice projects, I would say the same rule would apply.
List yourself and the role you payed, inline with the other project team
members.
If you do not have a formalized portfolio,
and will just be bringing a few rolls of Drawings;
(not quite as efective at showcasing your skills, IMO BTW...)
I would suggest 1/2 size sets. No need to fumble around with Paul Bunyan
size tree trunks of paper. You may even decide to edit the contents of the
set, to only include drawings that you drew, or coordinated the Work.
If you do plan to only bring construction drawings, consider taking a few
photos of the completed project, and bring them.
and never leave them behind.
If you want to attach a digital portfiolio to your reume, cover letter, etc.
always make it a protected format like PDF, or DWF.