When you print a document created with MSPAINT, the image is not adjusted for video resolution. This may cause MSPAINT printed images to be very large or very small.
The best way to print a MSPAINT image is to paste the image into a Wordpad document, or similar document, and print that document.
NOTE: You can resize the image in Wordpad. The image is actually converted to a Windows Meta File (WMF).