Although Blackout Fabrics are exactly that - they do not let light pass through them - it is important that Customers are not under the impression that the Perfect Fit system creates a total blackout solution. Even with blackout Roller and Cellular fabrics you should expect light ingress around the frame perimeter albeit to differing degrees based on the blind type.
Cellular is the most effective blackout textile offering around 90-95% light block. 100% is only possible with cassette blinds, a totally different product altogether. Perfect Fit is all about the framing system which allows a non intrusive, hole free window shade fitting solution, it is not a cassette system.
When a fabric, particularly cellular, is of blackout structure it will have a backing that prevents light passing through it. This backing will alter the facing fabric colour dramatically and therefore it is strongly suggested that when ordering samples both states of opacity are requested. Assuming that the blackout version of a fabric will have the same colour and tones of its translucent counterpart comes with a guarantee that it never does. So please do not hesitate to request samples for both opacities to ensure you are aiming in the right direction of choice.