Electrical tape. My dad firmly believes that electrical tape can be
used to fix anything, from lamps to broken hearts. I’ve used it here to
give my balcony wall a temporary Mondrian kick. 
To do this you’ll need:
- A roll or two of electrical tape
- a spirit level
- a few coloured acetate sheets
- a craft knife.
First give the wall a quick swipe with sugar soap or something, as
stickiness and dirt are mortal enemies. Next roughly plot your design
on paper, it doesn’t have to be to scale or anything.
Now you’ll need to create a ‘frame’ for your
piece. Mark out the long lines using a spirit level and a pencil then
apply a one long piece of tape for each side, pressing it down firmly
as you go 
Next mark out your design in pencil, again, using your trusty spirit level. 
I did this one square at a time, so I could make adjustments to my design when something didn’t look right.
Then
comes the tape, I wasn’t too fussy about getting the lengths exactly
right as I trimmed the excess off with a craft knife. If you’re worried
about scratching your walls then a bit of measuring might be in order.
To attach the acetate bits you simply cut them to size then tape around their edges.
Keep going until you’re happy with the way your wall looks!
