Saturday, 24 March 2012

Etching Linoleum with Caustic Soda

Lino  Intaglio + etch with caustic soda

Isn't this gorgeous's by Jo Sculthorp who keeps a blog called the green room - check her out she's an interesting artist.  It's lino printed relief and she has used lots of caustic soda.

If you decide to use caustic soda on linoleum - then you need to get all the materials organised and prepared keeping in mind that caustic soda is dangerous stuff.
Having said that I don't want to put you off using it.   You just need to be sensible.

Items / Implements You will need


Rubber gloves

Maybe some eye goggles in case of splashes

Old newspaper to protect your surfaces

protective apron

  artwork by Steve Edwards - its a relief print but
 I just love what he has done with the caustic soda


Caustic Soda Granules

Wallpaper paste flakes

A glass container  such as a jam jar or similar to mix the caustic in.

A stick or old wooden spoon to stir the caustic soda mix

A Tea spoon and a Tablespoon  for measuring.

Cold water

You will need a lid  too, to seal it  if there is any leftover.  I can not remember how long this stuff keeps but I seem to have the impression that it does actually keep for  a long time.  We had some at the print workshop I go to (FDPW in Dunfermline) and Bill (our technician)  says he made it years ago - it still works !!

To Create Your Mix

Take your glass container and fill it one third full of water.  
Into that  sprinkle two teaspoons of the dry wallpaper paste flakes.
Mix this together and leave it aside for five minutes, during which time it will  thicken up.

Put two teaspoons of caustic soda granules into this mix and then  stir it with a wooden spoon or  stick. ( don't use metal !!)

The mixture will get warm but don't worry - this is just the caustic soda reacting with the water/paste.
I think its a good idea to get a pencil or biro and write a label to stick on the jar .e.g.,
"2 tablespoons caustic soda and 2 teaspoons wallpaper paste"
 also put the date.  The mix is  ready for you to use on your linoleum.

Of course before you apply the caustic soda mix to your lino plate you will need to consider if you want to first apply some 'resist' onto the plate.


I have to add here that I came across some old book where the person had made a walled off area on a lino plate using putty or modelling clay so I guess you could do that too - I haven't done that myself so don't know about the 'ins and outs' of that approach.

I have also heard that you can use sellotape and parcel packing tape.  Actually I did a little test area on a small piece of old lino and used the shiny buff coloured packing tape and made a hole in the middle of it.  I put some caustic mix on it and it worked the area covered by the tape remained unaffected.  You can remove the parcel tape by slowly pulling it off or one time I removed it using acetone or nail varnish remover or it may have been methylated spirits.

I have mainly used wax crayon as a resist and also scratch into it. I can sharpen a kids wax crayon to a very fine point and do fine lines or I can cover a large area and then scratch into that for the caustic soda mix to etch into.

 I like this method because I can remove the wax crayon later on by scraping it away gently.  If there's still a small amount left then this can be removed by placing  brown paper over the surface of the lino, placing  a heated clothes-iron on top of it, not too hot though.

Iona Johnson - Australian artist (she doesn't have  a website)       Lino etch

Etching ground (bitumen based)

You can also use the old fashioned dark brown (syrup like consistency) as a resist - I tend to stay a way from it because of the need to use white spirit or similar to remove it.  I am highly sensitive to the fumes from it (it makes me feel really ill).

TIMING - 1 hour max

The caustic soda  mix achieves its maximum etching effect on the lino surface  after one hour.  No point in leaving it on longer than that. You might like to do a strip test and do a band of say 6 areas to/  get 6 different tones.

Wash the caustic mix from the plate under a hot tap using an old  dish (washing-up) brush or toothbrush to clean the surface thoroughly.

You can create a good range of tones by using acrylic hard ground and caustic soda combined 

Bear in mind that by using the caustic soda to create darker tones than the natural tone of the lino surface when you wipe it with ink (as you would e.g.,  an etching or dry point)

in combination with Lascaux Acrylic etch hard ground ( which you can dilute to different strengths)
as well as the lines you make in the linoleum itself - I use a  "cheap-ish" etching needle which they sell for students to use.  They have a long wooden handle and sharp pointed metal tip.  I have also used a triangular-shaped plate scraping tool.   It has a nice pointy tip - you just need to wrap some tissue paper around the shaft,  to protect your fingers as you are holding/ using  it.

          Iona Johnson       lino etch (details as above)

Here is a link to the post I wrote re. the print edition,  I made for the Dundee Contemporary Arts, print studio portfolio exchange -  using lino and caustic soda with the Lascaux Acrylic hard ground.  I diluted to about 3 strengths.  `one part water to 3 parts LAHG, 2 parts  water to 2 parts LAHG and finally 3 parts water to 1 part LAHG.

The Lascaux acrylic Hard Ground is available to buy at Intaglio printmakers suppliers in London.
It isn't cheap - but it is such a versatile and useful product.  You can use it in a collagraph fashion on  a metal plate to 'edit' your plate.  Of course you can also use it for collagraph making, in itself.


  1. Hi Aine
    Great info thanks. CS etching formula is something I've heard about, seen finished results of but did not know 'how to', so thanks for this.
    From reading your notes above (re recipe and jar labeling) I'd like to have clarified - is it 2 'teaspoons' or two 'tablespoons' of caustic soda that one is to add to the mix?

    Also would you recommend that one could one substitute the w.p. paste flakes with a homemade wallpaper paste mixture?

  2. Before attempting this I would recommend that you read the Sodium Hydroxide MSDS. I'm planning on doing this with senior high school students and will have to complete a risk assessment!

  3. Glad this was of use to you as this is the approach with the blog.

    Its a TEASPOON

  4. Omg! Wow this is what you call a great art of etched glass, I really appreciate this kind of blog. Keep up the good work!

  5. Annie, great instructions thanks -do you find you need to use wet paper or will dry work

  6. Hi, Reference your comments on Lascaux Acrylic hard ground. It is very expensive and I object to paying £28 for 500ml of simple acrylic solution. I've had 30yrs experience with industrial acrylic coatings ~ BUT a cheap alternative is B&Q quick dry water based varnish, which dries in 20mins. You can speed up drying with hairdryer. Try it !
    . . . John of Highgate

  7. Hello - this is a wonderful resource for beginners like me! Thanks for all your work. Is it possible to use a hard ground and make marks in it before the caustic treatment like an etching on copper?

  8. Nice Blog, thanks for sharing the great information.
    Printing Malaysia

  9. Excellently described! Thank you ever so much! Sign me up to your news letters please!


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