I used this product with the Avery template 5388 from the Avery website and using Microsoft Word to print 3 x 5 cards and it worked great. The sheets are sturdy enough to take two passes through my Brother laser printer, printing first on one side and then manually turning the sheet over to print on the other side. After printing, the cards are easily removed from the sheet and have very smooth borders which look quite professional.
There are many options for printing great-looking birthday party invitations, but the most economical way is to print on a premium 16-point gloss paper. You'll also want to stick with a standard size such as 5-inch by 7-inch to keep your birthday party invitation printing costs cheap; however, when it comes to colors you can go with full color since this option really costs little more than black and white yet has much more bang for the buck. Beyond those options, you would be wise to get matching envelopes (also cheap) and have a hardcopy proof sent to your doorstep before you actually print the entire run. The last thing you want is for a mistake to go unnoticed until your invitations are printed, when it will be too late or too costly to make changes. A hardcopy proof does cost a few dollars, but it's cheap insurance that the rest of the run will go off without a hitch. Pass your proof around to friends, family members and co-workers so you can get more than just one set of eyes looking it over for errors.