Individual members can print their membership cards by logging onto http://my.scouting.org. Click on Menu > My Dashboard > the three line menu > My Profile then clicking on the icon that looks like a small membership card
Unit key 3 leaders can print membership cards for their units by logging into http://my.scouting.org, Click on Menu > the unit > Roster > select who you want to print a membership card for, and them click on the icon that looks like a membership card.