Dot matrix tags are printed on a tear and water resistant Tyvek material.  They are 3 inches tall and about 6.25 inches wide including the pin feed strips down each side.  Tags are printed one at a time, and come in fan folded continuous sheets with tear perforations between each tag.  This allows you to print short or odd numbered batches of tags with little or no tags wasted.  The impact printer and ribbon allow for water resistant printing on the tags.

Laser tags are a tear, water and heat resistant material which allows the toner to bind to the tag for water resistant printing.  Laser tags come in 8.5 x 11 inch sheets of 6 tags with tear perforations between the tags.  If you print short tag batches that don't evenly divide by six, you can end up with unprinted tags at the end of each batch that you can't reuse.  These can be set aside to hand write tags if you have a need for that, but they can't normally be run through the printer again once tags are torn from the sheet.