When working with film, a contact sheet is a special printout that shows every picture on the roll as a set of negative-sized images. A contact sheet serves as a handy reference to a roll's contents. In Picasa, you can print a contact sheet of any individual folder or label.
In the Picture Library, select a folder or label from the Folder List.
Choose Folder > Print Contact Sheet (). The Preview/Print Layout screen appears.
Make any desired changes to the options in the Printer Settings area. But do not select a Print Layout size; doing so will take you out of Contact Sheet mode.
You should normally select Shrink to Fit to ensure that you'll see each picture in its entirety. However, you can select Crop to Fit, if you prefer.
Ensure that the printer is on and ready to print. Then click Print.