DIY honeycomb grid?
 

Hi,
I've recently 'lost' the honeycomb grids on our Ianiro 8 lamps flos, and am wanting to replace them. Thing is, these come very expensive. Something I didn't remember (otherwise I'd surely have paid a little more care to them).
Anyway, any good suggestion or advice with regards to DIYing a couple of those? (material, resellers, etc )
Or else, what can I use to get a little more punch/throw from my flos?
Thanx