All of the fabrics on offer throughout this site are Blackout, that is they will not allow light to pass through either sun rays passing into a room or light outwards and therefore shadow as seen from outside your property. It follows of course, in the later, that blackout fabrics have increased thermal qualities over standard fabrics. However the degree of 'blackout' is determined by the type of blind that the fabric is incorporated within i.e. the amount of light that is allowed to pass due to application and technical allowances that have to be made in order to fit the blind and of course to allow the blind to function. WIthin each product type, as you go through our site, we endeavour to give you an indication of the amount of extinguished light within a room you would expect to achieve essentially from 80% to 100%. Unfortunately the term 'Blackout Blind' is an industry description that we feel creates a very general expectation and as seasoned professionals we are only too happy to share our expertise so please take time out to ascertain that the product that you are considering fits your individual requirement and needs.