Local ABC radio was interviewing an astronomer about looking at the sun. What surprised me was that the astronomer said that there are no pain receptors in the eyes that pick up the damage caused by the sun - and then it is all too late.
He suggested indirect methods, including going to a local observatory, or, facing away from the sun, hold a pair of binos with the big lens end facing the sun, while projecting the image from the binos onto a piece of paper etc.
As LittleJohn's post above shows, there's always the net.
I don't think it will be a big black spot - something about 3% of the diameter of the sun.