So let's consider a species of blind, sea dwelling, squid-like aliens.
They are sentient, intelligent and highly social. As their societies develop and their available knowledge increases they require a method of storing information without needing to remember it all.
These aliens are completely blind as they branched off from a species that lived primarily in caves and the water they live in is actually a murky water-based solution making vision less useful then here on earth.
They can however very effectively echolocate, sense nearby electromagnetic disturbances and feel the basic chemical composition of certain objects by touch.
Other then the difference mentioned above the body of water they live in is essentially the same as our own seas and oceans.
Given all this: What different methods of "written" communication would they likely develop over their history (as they develop new technologies and get access to new materials, etc), what would they use to write, write on? I am not asking about the language itself, the syntax, the grammar or anything like that. Simply and literally how they would write.
Idealy I'm looking for systems which would enable them to take advantage of their abilities (for example being able to "see" into objects via echolocation).
Note: I put "written" purposely in quotation marks to indicate that it can be any form of information storage as long as it is permanent and does not require someone to remember everything.
Note 2: As I said in the question, I'd like to know how they'd write at different points of their history, so far I've gotten adequate answers for ancient preindustrial times, but none for when they start mass "printing" or even further when they start using computers, machines, etc... I'd love for example ideas for how their computer's interfaces would work. Only speech?