On Glass and Ceramic
Introduction to Jo Howell
Artist Jo Howell has been using alternative photographic processes in the creation of artworks since 2010. Cyanotype has proved to be one of her favourite go-too processes for coping with lockdown. Different from other alternative photography processes, cyanotype is not as sensitive to light as some of the other chemical compounds, which makes it the perfect companion for the darkroom-less analogue lover. http://www.maverickbeyond.com @maverickart @maverickartjo
Cyanotype on Ceramic
Using cyanotype with ceramics may take a few attempts, and there will be many times when you just want to skip parts of the process or hurry the wash along, but patience is imperative. If you don’t do it right, then you end up doing it twice!
To gain results shown. You will need:
- Cyanotype chemicals part A and B
- Bisque fired unglazed tiles
- A sponge brush
- a UV lamp
- crystal clear varnish
- Cold water
I use jacquard cyanotype solution which comes as crystal chemicals. Follow the instructions on the back to turn into a solution with water. These solutions should be made up a few days before you start.
When you are ready to do you tile, mix approximately 10ml of each solution into a container big enough to take your sponge brush. The wider the sponge brush the better. You do not want to have too much solution in the tile. A wide brush will mean you need less passes across the surface with the brush, and therefore, it will give you a more even covering. The tile is extremely porous. In low light you should be able to see that you have covered the whole tile as it will appear slightly yellow. The solution will be absorbed very quickly, try to avoid the impulse to put more solution on!
As soon as the tile is covered. Arrange your digital neg or flowers underneath your UV lamp. Exposure times will rely of your exposure unit. Mine is a 20 watt overhead lamp, which takes approximately 40 minutes to fully expose.
To wash your tile run cold water across the top straight from the tap for approx 5 min. Fill a tray and let it soak in cold water for 10 minutes. Change the water and do another 10 minute soak. Let the tile dry overnight. Some chemical may want to leach out. Place kitchen roll underneath and dry flat to void tide lines.
You may want to repeat you wash stage once dry. Allow your tile to DRY FULLY before you apply a thin layer of varnish. This will help you to avoid air bubbles and mould.
A thin application of varnish will help you to avoid discolouration from the varnish drying.
Cyanotype on glass
This is still a process that I am working on to perfect, but I can share with you the tests achieved so far, and then you can make your own decisions about how to proceed. There are many different ways to achieve results, I can only tell you my own experience and show you how it played out!
Above image shows poured gelatine solution on one side, and a thin layer painted on the back, to create a very faint double exposure. Pouring the solution gives this lovely vibrant Prussian blue. There are pros and cons to both forms of application.
To create cyanotype gelatine for on glass you will need:
- gelatine crystals for cooking
- a light tight container (I use old bottles from previous chemicals bought)
- a tea strainer or small sieve
- cyanotype solutions A and B
- a large mixing bowl or saucepan
- a smaller bowl that fits inside
- glass rod or plastic tea stirrer
I followed the directions for creating a pint of gelatine, but adjusted the amount of water down so that I could keep it in my container. Pour a small amount of boiling water into the saucepan. Put the small bowl inside the saucepan, this will act as a water bath heater. The gelatine is effected by burning and can spoil. Slow gentle heating and mixing is required.
If you have a glass rod for mixing then use that as it is chemically inert. If not use a plastic tea stirrer or similar. Add your cold water to the inner bowl, add your gelatine crystals and slowly heat and stir until dissolved. Add 25ml of cyanotype A and Add 25ml of cyanotype B (already mixed and ready to go as stated in the ceramic note). Take the gelatine off the heat continually stirring, then pour through the sieve and into the light tight container.
This mixture will need to cool down and settle for at least 24 hours prior to use. I tend to just pop mine in the fridge.
For printing on glass you will need:
- glass to work on
- kitchen roll
- acetone (nail polish remover)
- somewhere dark and dry to set the plate
- drying rack
- objects or digital negatives
- vinyl gloves
- Large mixing bowl
- Small mixing bowl to fit inside
- Sponge brush (optional)
The glass needs to be super clean. Spend a good amount of time going over the glass with acetone and kitchen roll to remove all grease. Any grease or dirt will cause the gelatine to pool around it. Put boiling water into the big mixing bowl and place your gelatine container into the boiling water to heat up. I don’t reheat on the hob. I just use the boiling water to gently heat the solution back up. The cyanotype and the gelatine will be impossible to work with if it gets too hot. The glass that you are to work on should be slightly warmed, you can do this in front of a heater, with a hair dryer, or using a tray warmer.
POURING TECHNIQUE – if you opt to pour the chemical onto your glass you will need patience and a steady hand. Pour the liquid gelatine solution onto your glass until approximately 70% is covered. Carefully tease the gelatine out to the edges of your glass. You can do this just with gravity or with a glass rod. Run the excess gelatine off a corner and into your small bowl. You can strain this excess solution and put it back into your light tight container later. If you are drying up right in a rack remember to turn the glass occasionally as the gelatine will pool at the bottom.
BRUSHING TECHNIQUE – this is physically an easier way to achieve a nice even coat if you aren’t so confident with the above pour version. Use the largest and cleanest sponge brush that you can find. Pour some of the warm gelatine solution into the small bowl. Mix with gently, so that the sponge soaks up a good amount of gelatine solution. Using as few brush strokes as possible coat the glass. This will give you a lighter blue colour and won’t give as thick a coating on the glass.
However you have chosen to coat your glass. Once it is coated, place in a safe dark and dry place to set for 24 hours. The exposure times will depend on your set up, but my exposure times were 30 min on the UV lamp. Fill your sink or wash area with VERY COLD water. Gently slide the glass into the water. Gelatine side up. Let it sit in the water for 5 min. This will allow the cool temp to set the gelatine. Gently agitate the water until the yellow is gone from the glass. Carefully dry for another 24 hours.
The two above images show where my gelatine has started to come away from the glass, this was because my wash water was slightly too warm to the gelatine didn’t set.
If you make a mistake, as above, the gelatine can be washed off with warm soapy water, and you can start again. You cannot do this with the ceramic tiles as once the cyanotype is absorbed, it will always be there.
Good luck! .