If you are looking for a full colour personalisation in a variety of places then UV printing is the best method of customising your portfolio or box.
UV printing uses a large flat-bed multi colour ink jet system to print. The ultra violet light immediately cures the ink, so there is no drying required at all.
As there as no dies involved, the size of the logo can be as big or small as you and in as many places as you like. Please note though, it is an image printed onto your portfolio and as such may not be as sharp and vibrant as a foiled logo.