There are a few reasons we might use a computer printer for printing a composed letter. One of the reasons may be to have a saved digital version of our correspondence. Using a Word Processing program like Microsoft Word or LibreOffice writer, a letter can get typed up and printed. The printed copy is sent and the file remains on our computer for reference.
An alternative to using printer ink to print would be to create a handwritten letter using pen and paper. If you’re an avid recycler and enjoy repurposing paper scraps, you can pick any pieces of paper to write notes on. Compose your messages, and then for a digital copy, use the scanner feature on a cheap multi-function printer. Your handwritten letter becomes the ‘printed’ copy. The saved scanned image becomes the ‘digital’ copy.
Instead of using the scanner feature on your printer, you can just create a handwritten letter or note card and take a photo of it using your smartphone.
The end result is that you create a more personal message to send, and with a scanned copy or photo of the handwritten letter, you can keep a copy for reference.
Sending mail with a stamp through USPS is a nice low-tech way to personalize and slow down life.