Prolific multi-media artist and jeweller Anna McDade uses copper etching extensively in her work and has generously written a tutorial explaining her methods, exclusively for the Guild of Jewellery Designers.

 

 

 

 

Tools and materials:

Copper sheet
Glossy laser printer paper
Coarse wet and dry paper (220-240 grit)
Standard domestic iron
Masking tape
Sheet of metal larger than sheet to be etched (this can be steel, copper, brass, etc, approx 1mm thick.)
Washing up liquid (preferably concentrated variety) – optional
Bowl or sink with water deep enough to immerse etching sheet
Sellotape
Parcel tape
Edinburgh etch solution (mordant) in plastic container, large enough to hold sheet to be etched
Rubber gloves
Dust mask
Wire brushes, various sizes - optional

Creating the transfer

Print your chosen design onto the glossy laser paper using a laser printer – I use a Samsung CLP300 that cost around £60 two years ago – this budget type laser printer is perfect for producing transfer sheets for etching, as the toner quality is not brilliant for printing – so it readily transfers from the paper to the metal – you can also buy unbranded toner cartridges for these models easily and very cheaply – around £20 - £30 for a full set.

Note: images must be pure black and white to work effectively as a transfer, and should have a good, clear linear quality.

Cut the print to the size of the metal sheet you are planning to etch.

Degreasing the sheet/plate

(As this process is used in printmaking, I often refer to the sheet to be etched as a ‘plate’)

This is probably the most important and difficult part of the process – your plate must be absolutely free of grease, otherwise the toner will not stick to the surface of the metal.

Begin by thoroughly sanding one side of the plate with dry wet and dry paper – you want to make sure that the surface is completely matt. Make sure you hold the plate by the edges at all times, as any fingerprints will transfer grease to the surface of the metal.

You can sometimes get away with wiping the surface with a dry towel, but generally it is better to smear neat concentrated washing up liquid over the surface with clean fingers, and thoroughly rinsing with fresh, clean water, preferably cold.

 

 

 

Tip: Check to make sure the plate is fully degreased: immerse the plate in water and slowly lift it out, holding it level (making sure you are holding it by the edges!): you should see the water ‘float’ on the surface of the plate: if it ‘crawls’ back in any areas, then there is grease there and you need to get rid of it – repeat the previous steps in those areas.

Dry your plate: you can do this with a hairdryer, by standing it on it’s side and letting it drip dry (if you’re really patient!) or you can place it on a hot, flat surface – I often use one of my radiators or the top of my wood burner, if in use!

Transferring the image

 

 

 

 

 

Place the paper transfer face down onto the degreased surface of the plate. Tape one edge with a couple of small strips of masking tape: tape half of the tape onto the paper and fold it over and under the plate. If any of the tape’s glue adheres to the degreased side of the plate, you will need to sand this off after the transfer process and before the etching process, as the glue will create a ‘resist’.

Place the plate transfer side up onto a metal plate – I use an A3 size sheet of mild steel, 1mm thick – this will transfer heat back up into the plate when the iron is placed on top of the plate. Place a hot iron squarely on top of the transfer and plate, making sure as much of the plate is covered by the iron’s surface as possible – leave for approximately 2 minutes. This ‘tacks’ the transfer to the metal – the next part of the process requires some heavy duty ironing action, so you don’t want the transfer to move as this will smear the toner and give an undesirable transfer finish.

 

 

 

Note:  you can use any kind of iron you want, but if it is a steam iron, make sure there is NO water in it! Mine is an Asda cheapie, which cost around £4, I have it set to linen, but you may need to experiment to get the right temperature, depending on the type of iron you are using.

Once you have ‘tacked’ the transfer to the plate, you now need to spend around 5 – 7 minutes firmly ironing the transfer onto the metal – I use the forward tip of the iron for best results – make sure you get every part of the surface doing this, you need a good, firm pressure – if your arm doesn’t ache half way through (and I often take a rest at this point and sit the iron on the plate again for a couple of minutes, as I did in the ‘tacking’ process), then you’re not pressing firmly enough!

Important: wrap a thick cloth around the fingers you are holding the plate with – it gets extremely hot!!

 

 

 

 

Note: Assessing whether the image has successfully transferred at this point is difficult to gauge, and comes with experimentation and experience, but a few indicators are: The image begins to show clearly through the paper: The paper lies evenly and flat on the surface of the metal, without bubbling (it will bubble slightly later as the plate cools, but should be flat at first.)

Allow the plate to cool, then immerse in cold water until the paper darkens, indicating saturation.

Removing the paper backing

The thicker top layer of paper should peel off easily at this point, leaving a thin layer of paper plus toner on the surface of the metal. You can use firm pressure of thumb or fingers to roll this paper layer from the metal, leaving just the toner: If you have some fine detailed areas, you may need to ‘scrub’ these: I find the wet paper backing ideal for this – don’t worry about taking off the toner – if it’s properly adhered, no amount of scrubbing using this method will remove it!!

 

 

 

 

 

 

 

 

 

Dry the plate, using the previous method described. There may be some residual paper fibres still stuck to the back of the toner on the plate, don’t worry about this, it will not affect  the etch. If some paper still appears between the toner, you can blot these lightly with some cellotape. Small areas can be touched up with a permanent pen, such as a Sharpie.

Preparing to etch

Using parcel tape, cellotape or other plastic tape available, cover the back and edges, as you only want the mordant to ‘bite’ through the front of your design.

 

 

 

Note: I find if you sit the plate on the edge of a surface (eg a table) and place your thumbs across the top of the tape as close to the corners of the plate as possible, holding the tape taught, you gain the most control over where the tape is placed.

Placing the plate in the etch solution

Wearing rubber gloves, sit the plate at an angle (so that the design is face down) to allow “drop off” during the etching process. Time will vary, depending on the strength of the mordant – for fresh mordant, check the plate every 30 minutes: for older, more used mordant, every hour will be fine. Remove when you feel that the depth of the etch is right for you, and rinse thoroughly in clean water. Allow to dry.


Note: Different concentrations of Edinburgh etch will produce different results, as will the angle at which the plate is placed in the mordant. For a grainy etch, add more citric acid to the mordant than the standard recipe indicates. If you place the plate at a fairly upright angle, you will develop vertical lines on your plate: this can be minimised by increasing the angle in the mordant (so that the plate lies closer to the bottom of the container): I have used upturned glass tea light holders to rest the plate on in the mordant, though it is necessary to move the plate slightly every so often, otherwise you can produce a resist where the surfaces touch.

Finishing

Remove the parcel tape backing.

 

 

 

Tip: sheet metal tends to come with a plastic backing and this can be left on the back of the metal throughout the process: this makes the removal process at the end much easier: otherwise you will probably have to sand the back of the plate as well as the front, particularly if you intend to form it into a piece of jewellery.

Sand the toner from the plate using the wet and dry paper. I strongly advise wearing a good dust mask to do this, as the toner dust is very unpleasant and not good for your lungs. If desired, use wire brushes to clean up the plate, or use your own preferred polishing method.

 

This demonstrates how fine the linear quality can be.

 

 

 

And the original image, before being prepared as an etching transfer.

 

Anna's work can be seen at : http://www.annamcdade.co.uk/
She has also been selected as an entrant in The Craft and Design Awards 2011 : http://www.craftmaker.co.uk/annamcdade/

 

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