You can create some beautiful effects with cling film, the patterns sometimes look like cracks. I have used cling film on all the pictures on this page.
Using bleach on the inks can create some striking lighting effects as well. The best inks to use for this are non-permanent and non-waterproof. For me Seawhite Drawing Inks are perfect for this. They also take a bit longer to dry, which is perfect when working with cling film.
Details about Seawhite Drawing Inks and where you can purchase them can be viewed in my post Seawhite Drawing Inks
How to use cling film on inks
1) Wet a sheet of cartridge paper with water using a brush
There are many weights of cartridge paper available, but I find 220gm paper ideal to experiment with, especially since it is cheaper than water colour paper. However, water colour paper is the best option for more finished pieces.
2) Apply coloured inks to the wet paper with a brush
You can do block colours going straight across the paper, which can be seen clearly in the "Cling film on inks" picture below, or you can apply different colours randomly on the paper, which can be seen clearly in the "Heart" picture above.
3) Put a piece of cling film on top of the wet inks
Take a piece of cling film and put it on top of the wet inks. For the best effects make sure the cling film is creased when it goes onto the paper. This happens pretty much naturally, but you can always make a few more creases. It is the creases that will help create the patterns.
You will also notice that when you put the cling film on top of the inks, the inks will move around and create different patterns of colours. This creates some wonderful and unpredictable patterns.
4) Let the piece of paper dry completely before removing the cling film
Let the piece of paper dry completely. I usually find 1-2 hours enough. Once it is dry, remove the cling film and you will see your ink picture completely transformed. It's like magic!
The piece below was the first one I created using cling film. The effect of it looking like an icy surface completely surprised me. Both inks and cling film are very unpredictable, which makes them exciting to use.
Adding details using soft pastels and bleach
After removing the cling film, you can add details to your picture using soft pastels. After removing the cling film on the "Heart" picture above, I noticed the heart shape on the right. I highlighted the shape further by using a red pastel to make the outline more defined.
You can also use bleach to create some striking effects. I have used bleach in the picture below to create the lighting in the sky. I used an ear bud to apply the bleach, but you can use a brush to apply it as well. You only need a very small amount of bleach.
I then used a white pastel to soften some of the areas, and create lighting effects both at the top and bottom of the page. You can also darken colours or make them even more vibrant with soft pastels.
I have used bleach to create patterns, which can be seen in the "Bleach on inks after cling film was removed" picture below.
Using Oil Pastels
Oil pastels are great at forming a barrier to the inks and water, so you can use it to create patterns before applying water and inks to the paper.
I have used an oil pastel in the "Cling film on inks and oil pastel" picture below. I used a white pastel to draw horizontal lines toward the bottom of the page and I also drew some vertical long leaf shapes on the left and right sides.
I then wet the paper with some water and added the colours to it. I put some cling film on top of the wet inks and then removed it after the paper had completely dried. You can see the parts which were drawn with the white oil pastel.
The great thing about these experimental pieces is that you can enjoy trying new things and seeing how it works. You can find some more ways of working with the inks in my post Experimenting with Inks.
Working freely means you will be constantly surprised by the results, and as I mentioned before, the unpredictability of the inks and the cling film makes them very exciting to use.