It can be printed, but is best viewed on screen because of the color. It allows you to display structures in several different modes and color schemes, and to selectively edit portions of a protein or nucleic acid structure for viewing. Rasmol 2.6.4 is more bug free, but Rasmol 2.7.1 has more features. Here's help on how to use RasMol. The initial screen appears as a search request form.
Many papers showing protein structure now list the accession number.
If you don't know the accession number or you wish to see what else is available, enter the protein name in the keyword space. Enter membrane protein porin and click the search button. You should now get a list of porin entries in the Protein Data Base. Then proceed as for case 1 to get the Rasmol file. Save it as 2POR.PDB .