we ordered infrared blocking foil from a company called ifoha. Unfortunately the website is either in Dutch or German. This is the one we use for our FTIR setup.
We used the one with product number:1201520. It does help to get better results in daylight. But unfortunately it darkens the image of the projector. The rosco-grey blocks a lot of ambient ir-light too by the way.
As i still don’t have a projector, i could not test it yet.
But for all who are interested there is a great example on using rosco black/grey and drafting vellum as projection material (with pictures) on this blog: