The optional diffuser filters available from Martin for the MAC 101 Series (Set of 8 x medium-angle diffusers for MAC 101, P/N 91616018) have a matt side and a shiny side, but the MAC 101 Series user manual does not explain which way these sides should face when a filter is installed.

When installing a diffuser filter in a MAC 101, turn it so that the matt side faces inwards towards the LEDs and the shiny side faces outward towards the front of the fixture.

Remember also that, as stated in the user manual, best results are obtained if the spill ring is removed when using a diffuser filter.