I have 1 line on my rear window not heating. Is there a simple fix?

I have 1 line on my rear window not heating. Is there a simple fix?

You can buy a special metallic paint that you put on to bridge the break in the wire (only any good if you can see where the breakage is). You also need a very steady hand and I would recommend using a finer brush than they supply (or paint it on thick, and trim back to a thin line with a blade).

It's year's since I used this stuff, but Halfords used to stock it.