Introduction: How to Etch Aluminum Panel Labels/designs With a Reusable Acid Mix

Picture of How to Etch Aluminum Panel Labels/designs With a Reusable Acid Mix

This tutorial will show you how to etch your own designs/labels into aluminum panels with a reusable acid mix instead of using electricity(the most common method).

It's a pretty good and cheaper alternative to profesional made panels for your home made synths, stomp boxes, etc. :)

As with any work involving dangerous materials, you'll have to be very careful and take any precautions needed if you are going to try this instructable.

If in doubt, don't do it!, and if you do it anyway and get hurt, don't blame me or this website, you have been warned ;)


Acid can burn holes into your skin, wear some protective clothing, gloves, eye protection and gas mask with the appropriate filter designed for acids before handling it!

When the acid mix reacts with the aluminum it starts to produce acid vapours that of course are dangerous to your nose and lungs so by any means, DON'T breath that!

If you feel like this is too much for you to handle, you are probably right and is time to stop reading this and look some place else, otherwise let's move on:

Step 1: Materials

List of materials:

-Some aluminum panel/s

-A nice design for the etching

-Laser printer w/ black ink

-Some pnp-blue sheets


-Eye protection glasses

-Protective clothing

-Hydrochloric acid (same thing as as muriatic acid)

-Hydrogen peroxide (same thing as oxygenated water)

-A shallow plastic container to mix the peroxide with the acid (2:1 mix, depending on the peroxide concentration you may need to change the mix, I used 11vol. peroxide)

- Another container with water to rinse the panel.

-***Extremely well vented work area*** try this only if you have access to any open and well vented area, the process creates some probably dangerous, and bad smelling fumes, beware!!!
-running water(avoid any metal tool/surface... metal kitchen sink is a no-no, unless you like to spend some $ on repairs )

Step 2: Print on Pnp Blue

Picture of Print on Pnp Blue

1.- Create your design in any vector app: Illustrator, Corel Draw, Ink Scape, etc.

2.- Flip the design before printing as you would with pcb etching.

3.- Print the design on regular paper sheet(100% scale), this will work as a guide to print on the pnp sheet.

5.- Cut a piece of pnp-blue just big enough to extend a little bit from the edges of your design on the already printed paper sheet, the extra length will help to print and transfer the design to the aluminum panel.

6.- stick the pnp blue to the printed paper sheet with some tape on each corner, use just enough tape to hold the pnp in place.

7.- Set the laser printer to high quality print, again, 100% scale.

8.- Print again, you should end with something like in the image below.

Step 3: Preparing the Aluminum Panel

Picture of Preparing the Aluminum Panel

Now that the pnp blue is ready to transfer, we need to prepare the aluminum panel, so:

1.- Cut the aluminum panel to the desired length.
2.- Use water sand paper to smooth out and remove any dirt/grease from the panel surface.
3.- Clean the panel with running water and dry with paper towels.

Step 4: Transfer the Design to the Panel

Picture of Transfer the Design to the Panel

Now we are going to transfer the design from the pnp-blue to the panel, same method as with the pcb toner transfer:

1.- Place the panel on some scratch piece of wood.

2.- Place the pnp-blue over the panel, make sure it's well aligned.

4.- Use tape to hold the pnp-blue on each side, make sure there are no air bubbles, wrinkles or deformations and the pnp-blue lies flat against the panel.

5.- Place some piece of cloth over the panel to protect the pnp-blue from the heat.

6.-Use an Iron to heat the toner on the pnp-blue, trying to cover everywhere, after a few minutes the toner will start to look darker, check from time to time to find any missing spots.

7.- When the toner looks black everywhere, the transfer is ready.

8.- Wait for the panel to cold down, then remove the tape, leave the pnp-blue in there.

9.- Now remove the pnp-blue, there may be some spots where the toner didn't transfer to the panel, we will fix that on the next step.

Step 5: Fix the Missing Spots

Picture of Fix the Missing Spots

As you can see on the image, there are some missing spots, we are going to fix those now:

1.- Take a sharpie pen(or any other indelible ink pen) and paint over the missing spots, retouch any spot 2 or 3 times to allow the ink to cover the spots and resist well the acid.

2.- Use tape to cover big areas/borders, etc.

3.- Picture #3 shows my panel, almost ready to etch.

4.- As you can see on image #4, I used the pnp-blue plastic left over to cover the back of the panel, this is important, you have to cover every part of the panel not going to be etched to prevent the acid from damaging the panel.

note: If the transfer ends up with a lot of missing spots or missaligned, you can clean the panel and start all over again, sometimes is better than fixing any mistakes.

Step 6: Etching the Panel

Picture of Etching the Panel


Acid can burn holes into your skin, wear some protective clothing, gloves, eye protection and gas mask with the appropriate filter designed for acids before handling it!

When the acid mix reacts with the aluminum it starts to produce acid vapours that of course are dangerous to your nose and lungs so by any means, DON'T breath that!

If you feel like this is too much for you to handle, you are probably right and is time to stop reading this and look some place else, otherwise let's move on:

1.- Go to a very well vented area, put on your protective clothing, gloves, eye protection and gas mask with the appropriate filter designed for acids before manipulating the acid, remember, don't do it indoors!.

2.- Use the shallow plastic container to mix the peroxide and acid in a 2:1 proportion, mix just enough to cover the panel and remember, ADD the hydrogen peroxide FIRST, then pour the acid slowly, to avoid any acid splashes.

3.- Place the panel into the container.

4.- The mix will start to react with the aluminum producing a lot of tiny bubbles, and acid vapours, DON'T breath that! , the acid will start to eat the unprotected parts of the panel.

5.- You can take out the panel and rinse it with water(another container with water will do) to check how is it going, take it back to the acid container if it needs some more time.

6.- Let it work until the groove depth left by the acid is about 0.5 mm, you can feel it touching the panel, or taking a closer look, remember to rinse the panel before any inspection, if you let it for too long, the acid will start to corrode the toner and damaging the protected areas.

7.- When the panel is ready, rinse it thoroughly with running water, remove all the tape and rinse it again.

8.- Here comes the green part, after the panel is etched, save the acid mix in a plastic bottle to reuse it another day, it will keep the strength to etch more panels.

Step 7: Painting the Panel

Picture of Painting the Panel

Now let's paint the grooves left by the acid:

1.- As you can see I didn't removed the toner, we'll do that later, prepare some space to be able to spray paint the panel, any automotive paint will work.

***note: you can remove the toner before painting the panel if you want, just use some old cloth or towel paper with nail paint remover (acetone) or thiner... but I'd say it's an extra step not really needed as you probably want to give the panel a smoother finish later with the wet sand paper, it will remove the toner too, but is up to you :)

2.- Cover every part of the panel doing several small passes, paint, let dry, paint, let dry, etc. so the paint sticks better.

3.- You should end with something like in the picture #2.

Step 8: Finishing the Panel

Picture of Finishing the Panel

Let's finish the panel:

1.- After the paint dries, use a water sand paper with a fine grit to remove the excess paint and the toner from the panel taking care to not over doing it on the recessed parts so the paint stays there.

2.- Rinse and dry the panel and that's it for panel etching.

On picture #2 you see how the panel will look with knobs.

btw. I'd like to thank a friend, without him telling me about his experiences with the magic mix(muriatic acid+ oxigenated water) and diy PCBs I would not come up with this variation on the theme, thanks simone, aka cimo :)


pdavis19 (author)2016-04-25

Just want to re-emphasize the point that you add the acid to the hydrogen peroxide, not the other way around. In chemistry we learned it as AAA - Always Add Acid. You never pour the acid and then add stuff to it. For example, if you have concentrated HCl and add water (or hydrogen peroxide, which is mostly water), the first few drops of water will immediately boil and splatter, splattering acid. If you add the acid to the water, the water will warm up, but because there's so much water than acid, it won't boil. Very important safety tip!

Also, for people who can't find Hydrochloric Acid, look for Muriatic Acid. Same thing.

design-centre (author)2015-05-19

negatives for desinn etching

aluminium concentration in etching process

holgerm.murk (author)2015-01-14

Great, but why would you need the hydrogen peroxide? It's aluminium after all.

sineSurfer (author)holgerm.murk2015-01-14

It gives extra oxygen to the mix and makes the chemical reaction faster ;)

pam.s.koontz made it! (author)2014-10-23

Thank you for this! I have an aluminum tray that my grandmother painted a beautiful design on in asphaltum. She never got around to etching it though! My dad has one that she completed and it's beautiful! I will use this technique to finish my grandmother's tray! She passed away in 1957, several years before I was born, so I don't know how old this tray is!

sineSurfer (author)pam.s.koontz2014-10-23

Hey, that's cool! try with some scrap piece first if you can to see how it will work, as it's not an exact science ;)

rizoma (author)2014-05-22

Hi there, anyone knows how that solition work in terms of recycling rese mg concern is that I dont wont to be harmful for the environment, I use this solution for PCB but in that case you can reuse that for yeas and there are even easy way to filter the copper back if you want to dispose the solution. Maybe I should look at electrolysis?

elabz (author)2009-04-02

Guys, I'm missing the important bit of info: what's a "pnp blue"? Is it a transfer paper of sorts?

The AntiGenius (author)elabz2014-03-14

Stands for "Press'n Peel". Many people like glossy photo paper better. Here's a link to a good tutorial using Staples' brand.

ColorfulNumbers (author)elabz2009-04-02

That refers to "Press-N-Peel Blue," a product for transferring a resist onto metal. It's used for making circuit boards

It comes in sheets. You print your design onto the Press-N-Peel using a laser printer or copier (but not an inkjet), then transfer your pattern from the Press-N-Peel to the metal using a clothes iron. If you place the metal into acid, any surface not covered by the resist gets etched away, but the protected metal remains.

Details on the manufacturer's website here.

dchall8 (author)ColorfulNumbers2009-09-11

Thanks to scriptster for asking about PNP and thanks to ColorfulNumbers for the reply. PNP stands for lots of different things. I had no idea this stuff was around. I wonder if the PNP will work to make a resist on fabrics?

The AntiGenius (author)2014-03-14

I Googled "pnp blue" and it came back press 'n peel blue. After chasing a link to a forum that had a failed link, I found this on the author's own website listed in his profile:

This is a procedure for etching printed circuit boards using Staples glossy photo print paper in place of PNP.

fudg (author)2009-03-26

you could always use asphaltum instead of the pnp-blue sheets. this way you can actually etch a hand drawn image if you wanted to. also, it would be easier to cover up mistakes with asphaltum if the pnp-blue sheets didn't work properly.

smokehill (author)fudg2009-04-02

Haven't heard of this stuff for years -- is it still available somewhere? Some time back I was trying to research how some early Marine Corps dogtags had the thumbprint etched on the back. My Dad's was the only one I had ever seen, from 1941. Eventually I found out that the USMC did this by painting asphaltum on the back, pushing the thumb into it, and giving it a quick acid bath. Apparently right after Pearl Harbor they cut out that step in the dogtag process to move men thru quicker, and never went back. I assumed it was some sort of petroleum product but had never run across it before (or since).

babycody (author)smokehill2013-11-10

Thank you smokehill for that information. My grandfather's dog tags also have his fingerprint. When I describe them to other people, I received the "this guy is full of crap" look. You just solved one of the mysteries of my life.

aristide202 (author)smokehill2012-08-06

Try the greasy smoke of a candle kept close to the plate, Wax will condensate against the plate surface and I think it may work in protecting metal from acid. But now I say why not try melt candle wax itself .
Anyway for home made asphalt try direcct hot boiling in some tuna can resin from any kind of pine tree. Stop boiling when it turns dark and thicker. A very interesting kind of free home made stuff mentioned in Noa's ark materials and then after.

smokehill (author)smokehill2010-04-12

I've done a bit more research on the old acid-etched Marine dog tags.  It seems there was another intermediate step I wasn't aware of.

Actually, it was the right index finger (not thumb) that was used,  and it was rolled onto the asphaltum mix on the back of the dog tag, much like any fingerprint is taken.  However, before the tag got the acid bath it was "fixed" by heating it over an open flame, apparently cooking the print into a hardened coating.

Only then was it dipped in a (basically nitric acid) mix to etch the print into the metal. Usually the dip time varied, between 30 - 60 minutes.  The whole process can be Googled up without much difficulty, using "marine acid dog tag" or something similar.  The old Navy instructions are in several places.

A quick Google and I found some here: I don't know this company, I'm just pointing to one possible source.

Apparently, asphaltum is also referred to as bitumen, though other reading seems to give differing definitions of the two.

I like your idea of using asphaltum (or possibly several other inexpensive paint-on products). You could print and cut out you pattern on regular paper, then use that as your painting guide.

If you aim at more artsy stuff, you could use colored wax too, cover the whole panel with wax, remove the parts you want etched with a needle or something like that. Easy to get( any candle will do) and resists the acid bath fine, but forget about precise drawings :)

Alcyon (author)2011-10-30

Does anyone know if you could do the etching with natrium hydroxide (cautic soda) ?

iTixle (author)Alcyon2012-08-11

Yes, if it is dilute.

msw100 (author)2011-08-06

Cannot buy Hydrochloric acid in the UK will anything else work ?

sineSurfer (author)msw1002011-08-06

Hi, I really don't know about a direct substitute for the Hydrochloric acid, have you tried asking for "muriatic acid" at a hardware store? that's where I get it locally.

Other option would be going with the original pcb etching method (ferric acid) look around here in the website, but ferric acid is too aggressive with aluminum, eats away the alu really fast so is not easy to control and most probably you will end with a faded etch, bot worth trying if you like a dirt/old/used/damaged look hehee.

Or go with electrolysis, see jeff-o comment.

Good luck!

iTixle (author)sineSurfer2012-08-11

Sodium hydroxide sold as drano could suffice. It would have to be a dilute solution so it would eat through it like butter, but it would work.

aristide202 (author)msw1002012-08-06

Well, I don't know what kind of acid you can find in UK. If you can't find anythig useful in some paint shop where art productcs are sold I suggest to try vinegar , lemon juice or some kind of cola drink. Cola is acidified with phosphoric acid instead of the usual citric acid . See phosphopric acid content in cleanining products against lime spots in steel sinks . Alluminium is not acid resistant as stainless steel and if you remove all traces of wax, oil or the like by mean of hot water and soap I guess you may reach a better result , Use cotton gloves ore some new paper towel in handling the dry aluminium panel against finger prints that contain some kind of skin grease . Make a test on a clean mirror for that. Test some piece of aluminium foil in cola or vinegar for one night and see what happens to clean metal.
I think of making a negative mask of the figure I want to etch then make a uniform heavy black spot on areas I don't I don't want to etch by mean of smoke o a candle kept close to the plate. .
Dish washing powder (very alcaline) could be interesting subject of experiments. I thik that clean aluminium does not resist to lon contact to theese acids, clean copper sure doesn't. I'll test it out this evening .

Imgunabeatu (author)2012-03-19


Thanks for taking the time to put together this tutorial.

I'm looking into acid etching a prop weapon i'm currently making at uni specifically the blade which is made of aliminium.

There's a couple of things I want to clarifty:

Is the black area the etched design?
What kind of tape did you use to protect the rest of the ali?

sineSurfer (author)Imgunabeatu2012-03-20

Hi Imgunabeatu, let's see:

Is the black area the etched design?

In the php sheet, whatever is not covered with toner (black) will be etched

In the panel, I painted with black spray paint the etched parts, without paint the etched aluminum looks dark gray and matte, if you like that look you can skip the paint.

What kind of tape did you use to protect the rest of the ali?

I went with 3M scotch magic tape as it sticks very well but is easy to remove afterwards, maybe packing tape can work too.

Try with a small alu piece before commiting with the blade so you can figure out the acid mix strength and etching times and get a better etching in your blade.

Good luck with the blade and don't forget to post a picture please ;)

Imgunabeatu (author)sineSurfer2012-04-17

Hey Sine,

Thanks very much for the reply.

I've just got hold of the materials. Hopefully have a crack at some testers this week.

Will do man. I'll let you know how it goes and get some photos up when I've got it done.

Cheers again man. Been a great help.

diegoeldeleon (author)2012-02-20

You can save some money using photo paper in the place of the PNP. but not any brand works. Best paper y have found for this (and for the PCBs too)
is "Apli Everyday" 180 grs/m or "Apli "Best price" 140 grs/m:

Some HP papers glossy are also good.

Sometimes if your print have a lot of ink area you'll need to put the panels in warm water during some minutes to remove al the paper.

siamonsez (author)2012-01-19

Did you do anything to protect the bare metal after the whole etching process is done?

sineSurfer (author)siamonsez2012-01-20

Hi siamonsez, not really as I like the matte look, but fingerprints show up right away. You can try with clear lacquer spray, or maybe aluminum anodizing, check this link:

lumpee (author)2011-11-20

ehmbee,you might try "ring the doorbell,the dog needs the exercise"

ryukyu (author)2011-08-18

I commonly do etching on PCBs which has the outcome of useable traces. What is the benefit or etching the metal to paint it? Is it simply to protect the paint itself?

sineSurfer (author)ryukyu2011-08-18

Hi ryukyu, "Is it simply to protect the paint itself?" sort of...

In this case, at least for me the final retro/industrial look matters too, have you seen a really old power tool or elevator? I bet they have lettering made using similar methods.

But yes, it does protect the paint from getting stripped from the panel, but you can do it if you are willing to :)

The point is... unless you have the proper stuff and supplies for screen printing which is how most of modern panel labeling is made nowadays, this is a quick and cheap alternative to create your own lasting labels and designs in anything made of metal.

josh1324 (author)2011-06-03

Is that for an atari punk console? Because I made one about a year ago, it was my first actual electronic project.

sineSurfer (author)josh13242011-06-03

hi josh1234, yes it is, great little project and now in a diy wood case :)

josh1324 (author)sineSurfer2011-06-03

thats awesome! Lol I have mine in a peoples jewelery case.

josh1324 (author)josh13242011-06-03

btw, I later changed the shity speaker to just a male audio jack.

trueblackdragon (author)2011-02-27

Danger! most aluminum etchants produce hydrogen in copious amounts! so no smoking or open flames please!!!

Remember the Hindenberg folks!

lazemaple (author)2010-07-13

I have 3% peroxide which is sold in drug stores and 35% peroxide which I think may be too concentrated? Also, do you add the peroxide to the acid or the acid to the peroxide?

sineSurfer (author)lazemaple2010-07-13

Hi lazemaple: I'd go with 35% peroxide as it should work faster, giving more oxygen to the mix to work with... maybe you want to try with a scrap alu piece first to test the etching speed And you must add acid to the peroxide, never the other way, the explanation: A large amount of heat is released when strong acids are mixed with water. Adding more acid releases more heat. If you add water to acid, you form an extremely concentrated solution of acid initially. So much heat is released that the solution may boil very violently, splashing concentrated acid out of the container! If you add acid to water, the solution that forms is very dilute and the small amount of heat released is not enough to vaporize and spatter it. So Always Add Acid to water, and never the reverse. extracted from here:

exlxaxd (author)2010-03-09

One thing I don't understand: What's the purpose of printing on regular paper and taping the PNP to it? Can't you just print the design directly to the PNP Blue sheet without the pre-printing and taping? Great instructable, by the way.

sineSurfer (author)exlxaxd2010-03-10

 Hi, is just to save on the pnp sheet, so you can see where the final print will be and use only enough pnp for the job,  no point on wasting it,  of course you can print just a small square or marks as a guide  and then stick the pnp to the paper ;)

airfoil (author)2009-03-22

would a photocopy machine work the same on pnp paper instead of a laser printer?

flyingpumpkin (author)airfoil2010-02-13
According to the PNP website you can use a laser printer or photocopier (as long as it uses dry toner which is most of them).  You cannot use an inkjet.
"An image is printed or photocopied onto this film, using a laser printer or photocopier (dry toner based), and subsequently ironed or pressed onto a cleaned copper clad board. "

sineSurfer (author)airfoil2009-03-22

It should work, just be sure to use a photocopier with high quality setting, you want enough toner on the pnp to make the transfer easier ;)

dr.Maligno (author)2010-01-01

hi from spain, did you used peroxide vol.11 or vol.110??

sineSurfer (author)dr.Maligno2010-01-03

 hola dr. Maligno!, I used vol. 11 as that's all I can get over here, a friend from Tenerife uses vol. 30 for pcb etching, he gets the pcb's etched in 25 seconds! you may want to try with 30 too :)

I'd do some tests on spare aluminum to see how fast the etching goes, as it can be to agressive and ruin your design.

dr.Maligno (author)sineSurfer2010-01-04

after doing some prove expreiments, i did try vol.10,vol25 and 30, but its too slow process. At last, i buy peroxide 110.vol and then the pedal become etched.

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