When you're putting in a new one of those filters with the grey lines which will turn red, are you supposed to be able to see the grey lines through the holes in the metal bit, or should they face the other way? (The instructions are a bit contradictory.)
Does it make any difference to how they absorb grease if they're the wrong way round?
the grey lines should be upwards - ie you can't see them through the holes! wouldn't have thought it made much diffeence to its grease absorbing capabilities! I think it's more for how soon you see the red lines that indicate the filter needs changing