Printing a report with print sheets from the portal

It is my understanding that a print sheet uses a variant to make a connection between the variable settings set in the web portal and the variable / filtering settings that are used when printing a report. It is also my understanding that without a print sheet and variant that when a user prints a report from the portal that the printed report would not have the same filtering (variable settings) as what the user sees in the report. I have created a report and a print sheet that uses a variant, but when we view reports in the portal there is not a print icon... we can only print from the browser. Printing from the browser only prints what is on the screen, not a formatted report set up in the reporting agent. How do I print a report that uses a variant and a print sheet set up in the reporting agent to be available to print from the portal... i.e. display an icon to print the report? If you have a better or more detailed explanation of what a print sheet is and how to set it up, please include that as well.