How to preserve and prevent my drawings from smearing?

so... i draw pictures using graphite pencils, not charcoal. i really really want to get a portfolio to put all my art work in, but usually people only use those portfolios for things such as photographs because the pencil will smear onto the plastic page protectors. if i use that spray (cant think of what it is called...) that they use to spray on art or projects will it prevent it from smearing onto the plastic and ruining my picture..? or what else could i do? what other proffesional things could i put my art in?? please help!!!