Light and Privacy Control using Roller Blinds

Consider how much light you would like to be able to pass through the roller blind both during the daytime and at night. Think about the view through your window and what you might want to be able to see through your roller blinds during the day. Think about privacy and what can be seen from the outside through the window blind during the night.

Blackout fabrics

Blackout blinds provide maximum privacy as well as maximum solar protection. Roller blinds made with blackout fabrics do not allow any light penetration through the fabric itself. However a simple roller blind with a blackout fabric will still allow some light to pass around the sides, top and bottom of the fabric when the blind is closed. If you require the roller blind to stop all light then a system should be used which houses the fabric and mechanism in a cassette and side channel system and which has light controlling seals and brushes. If a roller blind fabric is not intrinsically a blackout fabric in its natural state then the fabric manufacturers achieve the blackout performance by laminating a blackout lining onto one side of the fabric or by applying a special coating to one side of the fabric. This process is done by manufacturers to many fabrics which are offered as standard products in their ranges.

Dim out & light filtering fabrics

All roller blind fabrics restrict light penetration to some extent. Therefore all roller blind fabrics that do not restrict light penetration completely as blackout blinds do can correctly be termed ‘dim out’ fabrics. Dim out fabrics let light into a room through the blind but the visibility of objects and views on the other side of the blind will, depending on the fabric, be almost transparent from one extreme (ie roller blinds you can see through) to barely shadows and silhouettes at the other extreme. Blinds made from this type of light diffusing fabric are sometimes known as sunscreen roller blinds.

Some fabric manufacturers now grade the dim out performance of their fabrics on a numerical scale. For example a light penetration rating of 5 for a blackout fabric would mean light penetration or ‘dim out ratings’ of 1, 2, 3 & 4 for all other non-blackout fabrics. A dim out rating of 1 would be a semi-transparent fabric which allowed the maximum light into the room, for example a voile or a sheer fabric. A dim out rating of 2 would be a mid to lightweight fabric. A dim out rating of 3 would be for a mid-weight fabric which allowed some light to filter through. A dim out rating of 4 would be a heavier fabric that allowed a very small amount of light through.

Other articles from the buyer's guide series:
Solar Control
Thermally Efficient Fabric
Anti-bacterial and washable fabrics
Flame retardant and sustainable fabrics