Help with etching copper plates for embossing

Different application, but I did a couple photogravure workshops a long time ago, and I have a vague memory of etching in stages using different strengths of ferric chloride. Also of conditioning unused ferric chloride with a copper penny before use.
One of these studios did steel-facing for longer runs (and then preventing oxidation is a consideration you don’t have with copper). The hardware for electroplating can be as simple as a tank and a battery charger.

Hi Husko-

The Ferric Chloride you are buying is intended to etch thin foils worth of material from a wafer; thus, it is possible you are asking it to act longer than it is required to, and so it is likely not potent enough for your needs. I do not know the specific gravity or potency of your etchant, but I would suggest a 45’ baume like that sold by most printmaking suppliers. You might look into different things to mix in as well such as citric acid or hydrochloric acid, but be sure to do this in a WELL VENTILATED AREA with PROPER PROTECTION (I can’t recommend chemistry like this without writing that in, sorry, not trying to be pedantic!)

Additionally, you may be leaving the plate to sit in a flat tray for extended periods of time, even if the etchant is strong enough- the copper is rusting off in an etched sediment for which floats up a little bit from the plate, but then falls back down and becomes a loose scum of flaked off oxidized copper.
This sediment actually inhibits etching, believe it or not. This is why yes, the better etching systems that are made out there for industrial etching either have the plate upside down in a bath that is agitated, OR spray the plate with the ferric to agitate.

So, going back to your bath—- The bath needs to be agitated slowly to allow the etchant to continue doing what it should. If you are not already doing this- try gently rocking the tray every 30 seconds, this should agitate the sediment and allow the etchant to reach the surface of the plate and continue etching.
As a sidenote, be sparing and small with your agitation. A lot of etching rooms are covered in little orange dots from ferric splashing everywhere, you wouldn’t want to make your room like those, so be careful of splashing.

You could get some stronger grade Ferric Chloride and also try etching in a ‘vertical tank’- I recommend checking TakachPress.com for tools, etchant, trays, a vertical tank, etc.; you can buy some better ferric by the gallon, for example.

Hope this helps, and good luck.

Also you should no need to steel face the copper for an emboss. Frankly, steel facing is used to preserve delicate marks and features which are microscopic, such as light aquatints or photogravure as Parallel mentioned. Unless you are doing many hundreds of impressions, embossing should be just fine provided you’re using an etching/intaglio press and felts. The plate will bend over time, but you can just bend it back lightly. The press use will actually harden the plate over time in a process similar to ‘cold rolling’.

I think if you can employ a technical change to get a deeper bite you should be happy with the results.

Again, good luck.

I am looking to do thousands of impressions with a female and male die on regular paper. 5,000 or 10,000. Can copper be okay or will it be to weak? And would brass be better? If so can it be etched the same way? Or can steel be etched with something for embossing with the same detail that copper can hold?

Thanks so much already for the helpful info.

As mentioned above, for getting good depth like .020 inch for an embossing die in a reasonable amount of time you would want to splash or spray the acid onto the die continuously. But plain acid will undercut the resist and not give you any kind of shoulder. You need that shoulder so the embossing doesn’t cut the paper at the edge of the image and so the male counter can release from the die at each impression. A nice embossing has a shoulder around the image that reflects light and shows off the dimensionality of the embossing. There are several commercial products available that you can add to the ferric so that by controlling the temperature and spray pressure you can control the side wall etching and get a nice shoulder. These chemicals are all fairly hazardous and the setup and all the chemicals won’t be cheap. If you are looking to make and use this kind of die on a regular basis and you want to get a repeatable process I would recommend that you contact one or several of the suppliers for this kind of equipment and supplies. If you express interest in buying their products they will explain to you how they work and how much they cost and so forth and that might clear up some of your questions. Also, if you only need a few dies from time to time you may find it much more profitable to have them made for you to your specifications and simply pass the cost along to your client.
Brass can be etched with the same ferric solutions but retaining a good shoulder with brass is problematic.The nice thing about using brass, besides that it is bit harder then copper, is that after the etching process the die can be further worked using hand and dremel tools to create sculpted, multilevel dies.
I don’t think any of the big commercial die makers sells steel dies for printers so it may be that steel is not necessary for these applications. They can be made though and are used in the engraved stationary industry as well as specialty manufacturing operations. Steel can be etched with ferric chloride in a splash tank but you won’t get a shoulder. One good thing about steel dies is that they can be case hardened and chrome plated which makes them nearly indestructable, but that might be overkill for the application and the budget.

In the real world of foil and emboss we buy emboss dies every day. We tried making our own mag dies for a while. but found that we get better work from copper dies with fiberglass cast counter plates. these are available from all of the major die makers, Owosso, Metal Magic, Universal Engraving or any number of other vendors. I understand trying to make your own dies, but with that kind of quantity it will pay to have a good die to start with

I agree with Clpx2, you are probably better off sourcing dies and discussing your needs with a supplier like Owosso. Their technical recommendations will make the difference between cooking up one cookie in your kitchen and serving 52,000 cookies a week from a bakery.

What kind of press are you working with?

Best of luck.

So hard steel can etched deep into a male with the same ferric chloride just like copper? And have the same detail.

I heard plating hardens it bit I’m afraid it could add thickness throwing off the space needed. And I don’t understand how a little bit of plating hardens it? And I heard plating correctly is hard and the small kits don’t work good. Anyone have experience with this?

I heard about the fibreglass being pressed into to die for a cast but don’t understand how that works because there will be no space for the sheet to fit since the fiberglass molded to the copper die will cause no space for the same paper?

Hoping someone knows the answers to any of these questions. I am thankful for the help.

Have done a lot of etching….45 Baume ferric chloride salt is slowest to act but most accurate…it can be added to with water …info on www…to dilute to c 31-32 Baume use a hygrometer to check that…it will be quicker but probably lose detail….especially working with text. Never found ferric to work with steel but then I do not know absolutely everthing,just worked with the traditional ways of making etching for 35 years.Used 1:4 nitric for quick copper etching but it will be crude with undercuts. Beter to use extraction do not just rely on a well ventilated room for ferric…as it decomposes or dries out it goes into crystals which can be inhaled etc…causing burns when it contacts moisture again eg on skin or moisture in lungs etc.

What is the web site? www…to dilute to c 31?

80 bucks (up to about 4” x5”) + shipping for a professional made die and counter wins my vote every time.the acid required is really quite nasty stuff and then to dispose of it legally is too much hassle for me.
Some medium sized die maker are giving up and CNC milling ev thing now. If I were wanting to get into die making, this is route I would go. Shavings are all recyclable.
It may be romantic to make your own dies but, financially, probably a loss in the end.

Husko check out http://m.nontoxicprint.com/site/mobile?dm_path=%2Fetchcopperandbrass.htm&fw_sig=140282cf207dee4d5510d50f56108133&fw_sig_time=1519296229614&fw_sig_premium=1&fw_sig_permissions=none&fw_sig_social=1&fw_sig_potential_abuse=1&fw_sig_url=http://www.nontoxicprint.com/&fw_sig_api_key=522b0eedffc137c934fc7268582d53a1&fw_sig_access_token=890c6556e62818da2dc1fe1b0a09b399efa41258&fw_sig_locale=en-US&fw_sig_session_key=7065aaaa962b8e658059708deba651e37a9ce6f8d9f85918eb1c3adaf2ad201e-25581632&fw_sig_permission_level=0&fw_sig_site=25581632&fw_sig_tier=1&fw_sig_partner=webs&fw_sig_is_admin=0&fb_sig_network=fw#3213

The Ferric tends to undercut as you go deeper, The way the old blockmaking trade made half-tones of useful depth was to do what they called ‘four way powdering’. One had a 4 inch wide very soft hair nrush, and a large quantity of what was called ‘dragons blood’ (yes really!) One stoked some powder against a slightly etched dot area, right left, and then fuzed the powder with heat. Then again with the powder left right and fuze again, then from you and away etc etc and finally the fourth way towards you. You ended up building an acid resist fuzed on powder, on the dot shoulder which would stand for the next ferric bite, and get more depth with no undercut, on the contrary, one got a sort of ideal pyramid shaped dot. I can vaguely remember actually having a go at this at the old London School of Photo-Engraving at Bolt Court in London EC4 about 1956 or so. Dragons Blood was I think fine ashphalt powder.