
The Joy of Aluminum Foil Lithography - Tomte
http://sparkboxstudio.com/the-joy-of-kitchen-lithography/
======
jeffdubin
This is a lightweight version of PCB etching. Fat (or other e.g. sharpie) as
the resist, aluminum foil instead of copper clad board, and cola as the
etchant.

If you like this process and are into electronics, you should check out the
process of creating your own printed circuit boards at home!

~~~
petre
You can use sodium hydroxyde as an echtant. It doesn't turn everything it
touches into stickiness like cola does.

~~~
tdeck
At least with copper, you can also etch using vinegar and salt. I've done that
a couple of times when I didn't have ferric chloride, and while it's slow it
works just fine.

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pacaro
This looks like a lot of fun, but would it really hurt to link to the actual
video, rather than a rabbit hole of links and blog in another language?

It feels like "we did this cool thing and took some photographs, but couldn't
be bothered to actually write it up"

~~~
Kliment
This is the end of the rabbit hole: [http://www.atelier-kitchen-
print.org/category/video/](http://www.atelier-kitchen-
print.org/category/video/)

~~~
quakeguy
Thank you so much for linking this site! Great for school/students projects!
Real Hacker Stuff!

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Rotten194
Here's a video of the same process (but using vinegar for the acid instead of
soda) that doesn't cost $8:
[https://youtu.be/tXaimUkCVU0](https://youtu.be/tXaimUkCVU0)

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bane
This is strikingly similar to the process used in modern offset printing. As a
young child, I grew up in a family printing business, and though I didn't
learn all the details (I didn't really have much interest in the printing side
of the business and spent most of my time in the then still _very_ early
digital prepress playing with the computers).

My earliest memories of it were marked by specialists doing digital typography
on specialist computers, one monitor was a green-screen where some kind of
markup was entered and the other screen was a raster monitor where the output
was rendered. Each block of text was "printed" on photographic paper, cut and
then sent to the "layout" department where it was taped or wax adhered to a
page. (If this is hard to picture, imagine taping each block of text from this
page [1] onto another piece of paper in order to layout the entire page.) The
process looked a bit like this [2]

Then the final page was photographed in a photography room and the negative
developed. On occasion a photographic "proof" would be developed to show the
final page layout and make sure there weren't any artifacts from all these
tiny little pieces of paper that were used to make up the text blocks.

Then the negative was used as a lithographic mask to "burn" the image of the
page onto a metal sheet which then went through some kind of chemical bath to
etch the image onto the sheet.

From that point the process was basically what's in the rest of this video
[3]. And one more [4]

My parents ended up selling their company in the early 2000's because the cost
of going "fully digital" from pre-press to print was just too expensive. At
that time, the process had completely eliminated the tape and wax steps and
the layout was being done entirely digitally in software, then printed onto
regular paper which was then sent to film. The rest of the process was simply
unchanged.

Big competitors had invested millions of dollars into equipment which
apparently was capable of eliminating parts of the lithography process and
color separated artwork could go almost directly from the pre-press department
to paper. According to the videos I've linked to, the industry is now using
laser etching to etch the image on the plates.

Many years later, this knowledge became useful when, in another setting, I was
being interviewed by a gentleman with deep experience in microprocessor
lithography and we hit it off when I mentioned my family's business and the
lithography process we used in printing. Nothing so exotic as what's used in
CPU production, but the basics are almost exactly the same. There's been some
great videos about CPU lithography posted here recently. Here's one of them
[5].

The guys who actually did the printing were an interesting sort. Small
businesses being small businesses, we needed cheap help. So my family first
started hiring Vietnamese immigrants escaping right after the war and training
them. When that ran out, they eventually switched to a variety of people, many
of whom were ex-cons. I learned a tremendous number of life-lessons from
watching those guys, many of whom ran presses as _artists_ , on how to and how
not to wreck my life. The guys who were reliable were worth their weight in
gold. The ones who weren't suffered from an unimaginable litany of self-
imposed life problems, mostly drug or alcohol related.

At any rate, thinking back, this is really how I got my start into computers,
hanging out as a kid in the prepress department. Some more to read [6]

1 -
[https://marketplace.canva.com/MABXLyRjyco/3/0/thumbnail_larg...](https://marketplace.canva.com/MABXLyRjyco/3/0/thumbnail_large/canva-
finance-review-article-magazine-page-MABXLyRjyco.jpg)

2 - [https://3v6x691yvn532gp2411ezrib-wpengine.netdna-
ssl.com/wp-...](https://3v6x691yvn532gp2411ezrib-wpengine.netdna-ssl.com/wp-
content/uploads/sites/default/files/story_images_2/20120914SAWG_fg07a.jpg)

3 - [https://www.youtube.com/watch?v=5LMU-
zB8Sro](https://www.youtube.com/watch?v=5LMU-zB8Sro)

4 -
[https://www.youtube.com/watch?v=pNZb7CXUjs0](https://www.youtube.com/watch?v=pNZb7CXUjs0)

5 -
[https://www.youtube.com/watch?v=NGFhc8R_uO4](https://www.youtube.com/watch?v=NGFhc8R_uO4)

6 -
[https://en.wikipedia.org/wiki/Offset_printing](https://en.wikipedia.org/wiki/Offset_printing)

~~~
anfractuosity
That's very cool, I'd not heard of offset printing before.

It's a shame your family had to sell their business, as from what you mention
it sounds like not all of the printing method changed.

I was wondering with the kitchen method, how you'd get a photo onto the foil,
but as you mention a laser could be used. One thing I was slightly confused
about, is, is it always necessary to use a coating on the aluminium for that
approach.

I guess you could also coat the foil with the photosensitive emulsion you use
for PCBs too, and then etch that.

~~~
bane
Yeah, I guess I omitted that step as I'm not _entirely_ sure how the actual
lithography was performed. I remember a large "camera" where the negative
would go into the top and the sheet would lie underneath. It looked vaguely
like the reverse of an old acetate overhead projector.

How the image was etched in that process I simply don't remember, but I do
remember the sheet going through a number of chemical baths and washings (and
being reminded to stay clear of the chemicals as a child).

So there may have been some phase where the sheet was treated with a
photosensitive chemical before going into the camera, I simply don't remember
the detail.

This link [1] seems to have some details.

It looks like the plates run for a little over $1/plate for the smaller ones.
[2]

1 - [http://www.offsetprintingtechnology.com/sub-
categories/offse...](http://www.offsetprintingtechnology.com/sub-
categories/offset-printing-plates/)

2 -
[https://www.valleylitho.com/acatalog/Valley_Litho_Supply_Pla...](https://www.valleylitho.com/acatalog/Valley_Litho_Supply_Plates__6.html)

~~~
HeyLaughingBoy
Guessing it was something like an Agfa photostat camera. We had one of those
at my first job. We used it both for making camera-ready art for ads (we were
a tiny business) or positive film to send off to the PCB house to get boards
made.

IIRC, the film was standard Kodak 8.5x11 size negatives and the processing was
pretty simple. I would do everything from initial tape & wax puppets to the
final artwork. Not what I expected to be doing in my first engineering job,
but it was fun.

I took a printmaking class sometime later. I think the litho "stone" is made
photosensitive and etched, but that aspect of the process is fuzzy. Most of
the class was about positive prints and I spent most of my time doing intaglio
and lino block printing.

~~~
bane
Yeah, that looks basically like the device!

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elipsey
Beautiful and so accesible, really want to try this. Also it amuses me that
the aluminum is etched with Coke. Polar bears shouldn't give that to their
babies!

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anfractuosity
Very neat!

I'm slightly confused what the oil is doing though?

~~~
Kliment
dissolving the soap, cleaning the unetched segments so ink can adhere to them

~~~
anfractuosity
Ah cheers, makes sense.

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tpeo
Aluminography.

It can't be lithography _sensu strictu_ if you're not using stone.

~~~
abetusk
Literally the definition of lithography [1]:

    
    
        The process of printing a lithograph on a hard,
        flat surface; originally the printing surface
        was a flat piece of stone that was etched with
        acid to form a surface that would selectively
        transfer ink to the paper; the stone has now
        been replaced, in general, with a metal plate.
    

[1]
[https://en.wiktionary.org/wiki/lithography](https://en.wiktionary.org/wiki/lithography)

