Painted Slogans: Inspirational Cardboards

So what do you do with all that old cardboard left over from boxes of cereal, crackers, chocolates, paper, shoes? I used to throw it out or recycle it but then I got an idea: why not paint on it? I was already painting as a hobby - mostly abstract and nonrepresentational watercolours. These were more doodles than anything else and I was buying rather expensive watercolour paper to undertake what essentially was a pasttime. So this use of refuse seemed to be an easy way to transform trash in...