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Cassette Blackout Blinds Side Tracks/ Channels Guides Room Darkening

Cassette blackout blinds by Bloc Blinds especially relevant in darkening a room where light presents a problem.  Bloc Blinds developed this unique cassette blinds with side tracks to block out light. Fabric is enclosed within a cassette profile. Aluminium, covers the profile in two colours, white or silver.  Manufactured in the UK, the cassette blinds with side tracks head rail has a height of 60 mm at the front and a depth of 45 mm.  Inside the head rail, a spring tension system plays a key part in the blinds operation.  The cassette blackout blinds side channels/rails/tracks/frames are 40 mm wide.

Cassette Blackout  Blinds With Side Tracks Or Rails

The blinds with side tracks works by allowing the fabric from the cassette box roll down into the side tracks.  In order to help with light leakage, brushes are found within the side channels. Small black pips aids to keeping the fabric within the side rails. Importantly, these smaller cassette blinds can’t be reversed rolled.

The cassette blinds provides a blackout blinds solution in domestic homes that are almost total blackout blinds. Of particular note, the cassette blinds with side rails are award winning providing an aid to sleep. In addition, these blackout blinds for cinema rooms provides an effective solution. The cassette blinds with side tracks are a perfect choice as domestic window blinds.

In order to fit in a commercial setting a fire retardant fabric is essential. For a bathroom, a PVC fabric is a must with the roller blind cassette system. In essence these are framed blackout blinds. The cassette blinds with side tracks are perfect for the domestic market.

New Blocout Polka Dot Pink blind in bedroom

Tolerances Built Within the Blinds With Side Rails

There is 5 mm tolerance on the drop and 6 mm on the width for the cassette blinds. However, when all widths are the same, then the blind will be made to the sizes given. In order to operate as spring blind, limitations are set to enable the blind to work correctly. The sizes are found below on the fitting range section.

Overall Benefits of Cassette Blackout Blinds with Side Rails

Blackout roller blinds without side tracks prevent  most of the light from entering a room and darken the room in general. In order to add blackout properties to the fabric, manufactures, add an additional layer to the back of the fabric. To a large extent, it is reasonably successful but it will not stop all the direct light from entering the room. Light bleeds through all sides of the fabric thereby causing a halo effect. Additional curtains helps the problem to some extent.

However, these Cassette blackout blinds formerly known as Eco Thermal Blinds otherwise Bloc 40 provides a solution to the problem. As the name suggests, the cassette roller blinds with guide rails keep warmth in a room during the winter and the cold out.  At the same time, they keep a room cool during the summer months. Especially, during the summer months when the sun rises early the cassette blinds are second to none in darkening a room. Consequently, the blinds prevents the sun light disrupting sleep as well as reducing tiredness.

The cassette blinds allows night workers, nurseries or those who are light sensitive to block out the light from the room. Thus aiding sleep and increasing well being and health.

The cassette roller blinds system provides a barrier, preventing heat loss from a room in winter. Keeps a room cool in summer.

As a spring operated blinds, there are no chains to pose a danger to young  children, vulnerable or animals. Thereby a safe by design product.

In essence, the cassette blinds are roller blinds with side tracks/rails and cassette head rail. A great solution as room darkening blinds.

0424 Amber Sunset Cassette Blackout Roller blind edge fitted

0424 Amber Sunset Cassette Blackout blinds edge fitted

Blocout Cassette Blackout Blind in 0321-lime-green in lounge

Blocout Cassette Blackout Blind in 0321-lime-green in lounge

Cassette Roller Blackout Blinds Fitting Range

  • Minimum Width 400 mm
  • Min Drop 300 mm
  • Max Width 1800 mm
  • Max Drop 1500 mm

Measuring Cassette Blackout Blinds

How Cassette Blinds With Side Channels Work

First of all the cassette blinds comes with a head box. In addition, Aluminium side channels are fitted to the head box. The combination of the head box with side channels enables a room to be darkened. Within the side rails brush seals run all the way inside the side tracks. Most noteworthy are the blackout cassette blinds black seals on the handle.  Pushing the handle towards the window allows the blind to move up or down. Releasing the handle allow the braking system to operate and stop the blind in the desired position. The combination of all these factors working together, enables the blind is able to block out almost most light. This is an important factor for blackout blinds with side tracks.

Uniquely, as the handle comes into contact with the window sill, it blocks the light from entering the room.  In other words the blinds in essence are a spring loaded roller blind with side rails.

Cassette Blocout Blinds Energy Saving & Cooling Properties

Secondly British Blind & Shutter Association tests, shows heat reduction up to 43% through windows.

While the binds construction enables savings of heat in the winter as well as, reduces draughts, it also prevents heat loss from a room. Rubber seals at the bottom of the handle create a barrier between the blind and the window sill.  Brush seals within the side rails aid in draught prevention for these blackout roller blinds with side frames.

The fabric forms a barrier between the room as well as the window thereby providing energy savings on heat costs. Consequently, heat within the room stays in the room. Especially important factor during any cold spell.

Furthermore, during the summer, the cassette blackout blinds with side tracks block out the sun and keep a room cool. Additionally, these Eco thermal blackout blinds are a trend setting blinds within the industry.

By the same token, all fabrics within the collection allow room darkening or keeping the room cool. A fabric with white backing affords the best energy saving blackout blinds. In addition fabrics with the same colour on both sides provide marginally less energy savings.  As a matter of fact, a thermal energy saving blind suitable for use in bedrooms, cinema rooms or nurseries. A wide selection of fabrics available. Buy Blocout cassette blinds online.


All the fabrics are in price bands form AB, B-F. The cheapest band is AB and the most expensive is F. The AB band is cheaper because of volume bought by the factory. This does not mean that the quality is much reduced. Other fabrics have special finishes which increases the cost of production for example the Night Night Glow, which glows in the dark.

Blocout Blinds Frame Colours- Cassette Blinds System

  • White
  • Silver

Cassette Blinds Safety

Third, the blind is spring operated without cords thereby It does not pose a danger to children or animals. Ideal in playrooms as well as children’s rooms. Equally, night workers, migraine suffers benefit from the Blocout system as a result of room darkening. A perfect nursery as  spring operated cassette blackout blind.

Difficult Windows

  • Tilt and turn windows
  • Dormer windows
  • Sash Windows
  • Bay Windows
  • Loft window send a photo or two of the window taken directly in front of the window

        Contact Us  In order to get help with these windows. Please send photos taken frontwards along with sizes of the  window opening.


Finally as a drill free product, the blind are easy to install. Necessary tools in order to fit the blinds include a hammer and screwdriver.

Fitting options available:-

  • Edge of recess- Fits on the edge of the window. Takes the least amount of time to fit of all the roller blinds with side guides.
  • Inside Recess/ Reveal – Batons 3 sides inside the recess. Blind fits onto the batons. The batons are 9 mm thick by 45 mm depth.

NB- Wood 9 mm thick by 45 mm deep prove helpful in squaring a window.  Alternatively, wooden batons enabling blinds to fit in the recess is available as an option. Additional charges apply.

Check fabric suitability, please order a sample. Check the fabric is suitable in day light and night light.

Blocout Cassette Blackout Blinds – Are NOT suitable for photographic rooms.  A specialist blind is available POA which provides 100% blackout. Contact Us for details and specification sheet.

Also, the blinds can be blown out of the side rails if a window is open and the blind is any thing from 2/3 rd’s down. This happens as a vacuum is created between the blind and window.

The same can result if the blind is part way down, the window is open and someone enters a room and the door slams shut.
Obtain an instant quote online for these light blocking blinds. In fact a quote is available for the cassette blinds online by entering the window sizes on the website.

 Fitting the Cassette Blinds With Side Tracks


NB To clarify, please be aware that the guide dogs for the recess fitted blind now come attached to the batons.

Other Fitting Videos available.

Maintaining Blackout Blinds with Side Rails

Provided that the blinds are lightly dusted, hoovered regularly as well looked after, they will provide years of service.

Windows larger than 1800 mm wide/ 1500 mm drop – Blocout XL 80 Larger system with side guides or use for surface fitted blinds.

Replacement Side Rails

Can you buy the cassette roller blind with blackout fabric with the side rails separately?

Importantly, replacement side rails comes as part of the whole system. Providing the cassette blackout blinds has been made by Bloc Blinds, it is possible to buy replacement side rails.


The factory is currently on 15-18  working days for these blackout blinds with side rails when fabric and components are in stock. Production times will increase if any components or fabrics are out of stock or the chosen fabric is digitally printed. The fabrics in this category includes many of the pattern fabrics.

Options for Larger Windows

See Commercial Cassette Blinds with side rails or Electric Commercial Cassette Blinds for larger windows as alternative options.

Of particular note, the cassette blinds with side channels can be chain or crank operated. Battery or mains are the options to control the electric blinds with side rails.


In conclusion, the cassette blinds with side rails are composed of a basic roller blind fitted inside a cassette head box with side tracks. Once the barrel is fitted into the cassette box the barrel with the fabric is not visible.

The success of the blinds depend upon correct measuring and fitting the blinds. The whole system is certainly the blind for the domestic market. In addition the choice of blackout fabrics aids in room darkening along with the side channels.

The blinds are not total blackout blinds  with side tracks but offers an almost blackout window solution.