Jonathan Bull

There are probably over a dozen different fly screen designs out there. But they all fall into three broad types, and knowing which one you're dealing with changes everything. Type 1: Sits inside a groove in the aluminium window frame These screens live in a channel that runs around the inside or outside of the frame. When the channel is on the inside, to get them out, you often need to remove the sliding window first, then the screen slides or lifts free from the groove.

After 25 years cleaning windows, I knew exactly what tool I needed. The problem? It no longer existed. So I did what any slightly obsessed tradie would do: I made my own. What followed was a crash course in plastic injection moulding, overseas manufacturing, and the humbling realisation that the more you learn, the more there is to learn.

Every window cleaner knows the feeling. You've carefully squeegeed the glass, stepped back, and there it is: a soapy dag, a mineral deposit, a stubborn mark that a microfibre won't touch. The answer, as all good window cleaners know, is 0000 steel wool. It's been the answer for decades. The problem has never been the steel wool itself. It's been everything about how you hold it.