I've talked on a few occasions about the Union Canal Carriers' 'window cloths' which I was extremely pleased to have bought for four pounds at the tat auction in Droitwich last Easter, but I don't think I have ever shown them in use.
There are two of them, each four feet wide by about eight feet long. They are made of translucent plastic reinforced with a pattern of woven fibre, and they have an eyelet at each corner.
This is what they look like from the outside when fitted:
They go over the top plank and over the side cloths and the eyelets attach with rubber bands (cut from old inner tube) and hooks to the gunnel rings. The top cloths then go over them, and can be folded back (although in this picture we have left a gap between the top cloths instead). Once tied down, they look quite smart.
They certainly make a difference on the inside, where they really do look like windows, nearly three foot square. Instead of an unusable pitch black hold, we have a big well lit space, so much more useful and welcoming.