The masking tape does not completely block out the IR reception. It just simply reduces it. However, if you use something opaque, like black electrical tape, then it will prevent you from controlling the TV's volume or power.
With the masking tape, you would have to basically "aim" precisely at the desired TV to be controlled, rather than pointing the remote in the general direction of said TV, as you would when controlling an unmasked regular TV setup.
Before I installed a URC control system, this masking tape solution worked perfectly. If you cut the masking tape neatly, one won't even notice that there is any masking tape there at all.
Hope this helps.
if I dont put any tape on it, what will happen? the two tvs are a pretty decent distance apart. i have a 40 inch samsung, then 60 inch panasonic, then 40 inch samsung. with about a foot inbetween each tv. not sure but i may be able to point remote away from tv i dont want to control.
also, would i want to do each receiver as RF or IR. and will it work if i put receiver behind the wall i am hanging tvs on.