[pastage]

It is degrading too fast, microfilm archives need to be digitilized now, the solvent and image chemicals and media are all part of the problem with microfilms. Archival paper is a nice medium that can be stored a long time. This is of course a question of how long you want to store your information if you want to do 00500 years it is probably good.

Or just go with metal https://rosettaproject.org/

Or try to create a culture for humans and store information in that.

[xyzzy123]

Metal engraving fairly accessible these days.

Fiber laser in 100W range would do it, maybe $10k?

You could do photochemical etching but would be more fuss and wouldn't last as long as a laser engraving.

Probably looking at order of 1gig/1000kg if using 1mm 316 plate (napkin math only, naive estimate). Interesting to explore.

[WorldPeas]

I would wonder if glass/plastic would be viable given the availability of dvd/modisc burning lasers (though the format is kneecapped by its issues with glue). Is there any good literature about “burning” nonuniform durable materials in a rotary disc burner or am I off base here wrt the capabilities of these smaller lasers

[xyzzy123]

> Is there any good literature about “burning” nonuniform durable materials in a rotary disc burner

Not that I'm aware of. A DVD write laser is maybe 200mW so it's not going to be able to engrave most materials or do it VERY slowly at best. The spot size is ridiculously small though (this is good) so they are still interesting.

Most people interested in light wood or thin plastic applications have moved on to the small 5-20W diode laser form factor, these are available for a few hundred dollars if you aren't too worried about safety (e.g. no kids in the house). Something with a proper enclosure, interlocks and air handling costs more but still sub $1k. The spot size is much bigger than a DVD laser though; you can't get anything like the same resolution.

Modding a DVD laser has much higher hack value but it seems to have gone out of style as hobby lasers became widely available as a product.

Re: materials, if you are not on the "happy path" (material supported by manufacturer or specifically designed for laser) you have to get samples and test.

There's a few different interactions with laser spot size, wavelength, power, passes etc and the material which means different people (with different systems) tend to get different results. The variability limits the "shareability" of results; probably the biggest sources material info / laser settings are in the forums of the laser manufacturers because it makes the most sense to share settings with other users of the same system.

As you noted, glue and nonuniformity are a big thing, most materials aren't designed to be burned / vaporised. For glass specifically I think the most practical way would be a CO2 laser which is different again.

[lifthrasiir]

Maybe. Anything that can be photographically etched and is durable enough would work well.

[tokai]

This. The right paper will last significantly longer than microfilm.