Suppose you want to pass down pictures to you great grand kids and you want those pictures to look just as good as when you took them. Right now there are many challenges to this problem because the media we use are mostly short term (30 to 50 years at most). Another challenge is the format, because formats are always changing and may not exist in the future. Hardware is another big problem since CD players may not exist either. Let’s look at how Nasa tries to solve this problem and what options us regular people have.
The Voyager Golden Records are phonograph records which were included aboard both Voyager spacecraft, which were launched in 1977. They contain sounds and images selected to portray the diversity of life and culture on Earth, and are intended for any intelligent extraterrestrial life form, or for future humans, who may find them.
For the rest of us there is something called Microfilm, but even this simple long lasting media is challenging for one to independently produce. One commercial entity I found that makes microfilm is: