Christmas Letter from Santa.net sells inexpensive Santa letter templates that you can personalize and print at home, but they also offer a free printable Santa letter featuring the same design as one of their paid products.
Of course, this free version can’t be personalized. It’s a pdf file with a generic letter from Santa, rather than the Microsoft Word file that contains the customizable Santa letter. But if you don’t have $3.99 for the MS Word template, the free one is a good option. You’ll get a high quality document that you can print at home at no cost. The design features two cute snowmen waving from the bottom right corner of the page and a light blue background bordered by a red-white-and-green candy cane stripe.
If you want to know what the letter says before you download it, you can almost make out the text of the letter in the image, but forget about straining your eyes to try to read it. The site provides a Santa sample letter with the full text of the premium letters. The free version is essentially the same with all the customizable elements removed.