• Delivered in 3 to 5 working days.
  • Chain Operated
  • Same Day Dispatch
Delivered in 3 to 5 working days.
Chain Operated
Same Day Dispatch

Bosa Slate Blackout Cassette Blind

Please Select

  • White Hardware
    White Hardware
    Standard Price
  • Black Hardware
    Black Hardware
£ 117.60
- +
order free sample

Delivered in 3 to 5 working days.

Available in Other Colours
Available in Other Colours
  • Oxford Blue
  • Denim
  • Admiral
  • Apple
  • Ash
  • Cherry
  • Chocolate
  • Cool Blue
  • Cream
  • Dusty Pink
  • Graphite
  • Grey
  • Ivory
  • Lilac
  • Magnolia
  • Marsh
  • Onyx
  • Pine Green
  • Pink
  • Plum
  • Primrose
  • Rose
  • Scarlet
  • Sunshine
  • Tangerine
  • Taupe
  • Toasty Grey
  • Turquoise
  • White
  • Ash
  • Cool Blue Reflect
  • Cream Reflect
  • Marsh Reflect
  • Onyx Reflect
  • Oxford Blue Reflect
  • Scarlet Reflect
  • Slate Reflect
  • Taupe Reflect
Product Description
Product Description

The Bosa Slate Blackout Cassette Blind is our Total Blackout solution to cast your room into complete darkness. The barrel and blackout fabric are neatly enclosed within the aluminium headbox and side channels ensure the edge of the fabric stays in place. As a result, this blind creates a light omitting seal, blocking light from entering the room.

Our total blackout cassette blinds are perfect for any room you are looking to banish daylight. From Bedrooms to Home Cinema Rooms, our cassette blinds will provide you with complete darkness all year round.

The Bosa Slate fabric is a Grey coloured blackout fabric made from Polyester. It is operated by a nickel chain that protrudes through the bottom of the headbox. This cassette blind can go to a maximum width of 2200mm.

Due to the nature of the light omitting seal created by this blackout blind, windows must be closed while this blind is down. Opening a window behind the blind could cause a vacuum resulting in the fabric being sucked from the side channels and resulting in damage to the blind.

Available in either a White or Black hardware finish full technical specifications can be found in the Geeky Stuff section below.

Not quite the right Blackout Cassette Blind option for you? Click here for a full listing of our Blackout blinds, and use the filters to help narrow your search.

Technical Specifications
Technical Specifications

Technical Specifications

Click here to download our full data sheet, which includes sizing charts along with component line drawings. 🤓

Our Blackout cassette blinds are designed, first and foremost, to provide darkness in a room by creating a sealed unit in or around the window.
To fit this blind you will be required to drill multiple holes, not just into the masonry you’re fitting to, but into the headbox and side channels themselves, as they don’t come pre-drilled. This is because you will need to ensure the entire blind sits squarely within a recess or against the wall, so you will need to decide where to specifically screw the blind to the wall.
The cassette blind is comprised of an aluminium headbox fascia in which the fabric on a barrel is held. Aluminium side channels run from top to bottom and are attached to the headbox. The fabric has fabric retaining pips attached to it, which hold the fabric in the side channels.
Important: When the blind is in operation, the window must be shut. Failure to close the window when the fabric is anywhere but fully rolled up can cause the fabric to be pulled out of the side channels. This can damage the fabric or the side channel and the warranty will be voided. Do not operate this blind with an open window. If you install this blind on behalf of someone else, please inform them.
At the bottom of the fabric is the bottom bar that has a pile seal on the bottom of it. This helps to form a barrier against the light at the bottom of the window when it sits on the bottom fixing strip.

The headbox for our standard chain cassette blinds measures 76.7mm high and 72.6mm deep.
The side channels measure 55.3mm wide and if recess fitted, the side channels are 29.5mm deep, and if face fitted, they are 25.2mm deep. Please note that recess-fit side channels cannot be used for face fitting and vice-versa as they are different.
The bottom fixing strip is 25mm tall and 21mm deep and will match the chosen hardware colour. This L-shaped metal strip is there to allow the bottom bar to sit just in front of it, thus creating another barrier between the window and the room.

The hardware is available in white or black, and this blind is operated by a nickel chain that can be on the left or right side of the blind.

We expect our cassette blinds to provide darkness in your room for standard use. However, we cannot guarantee absolute darkness due to differences in installation, location and light direction. Every care and attention has been made to engineer this type of blind to give maximum levels of darkness.

Click here to download our full datasheet, including sizing charts and component line drawings. 🤓

Blackout Chain Controlled Roller Blind Cassette System in Action

How To Measure
How To Measure

How to Measure

Achieving high levels of darkness takes a bit of consideration, time and planning, and so click here for a PDF of our handy instructions to cast a bit of light on the matter. Download our Cassette Blind Measuring Guide here!

How To Install
How To Install

How to Install

Planning the installation of your Cassette Blind? Good call!

🛠 Click Here to download our nifty Cassette Blind Fitting Guide! 🛠

Shop with Klarna
Shop with Klarna

Buy Now Pay Later with Klarna

DotcomBlinds is pleased to be partnered with Klarna, providing you with more ways to pay.

At the checkout you will see Klarna provides two options: Pay in 3 Instalments or Pay Later.

Pay in 3 Instalments

With Klarna’s option to pay in three instalments, you can spread the cost of your purchase across three interest-free monthly payments.
To pay with Klarna’s ‘Pay in 3 Instalments’ option, you just need to be a UK resident over the age of 18 years old and have a valid payment card.

Pay Later In 30 Days

The second Klarna payment option you’ll find in the checkout is to buy now & pay later with their ‘Pay Later in 30 Days’ option at the checkout.
With this payment option, you make your purchase now and don’t pay until 30 days after we have shipped your product to you, giving you plenty of time to save up!
To pay with Klarna’s ‘Pay Later in 30 Days’ option, you just need to be a UK resident over the age of 18 years old and have a valid payment card.

If you have any questions, please don’t hesitate to get in touch with us.

Next Day Free Samples
3 Year Warranty
3 Year Warranty

3 Year Warranty

A blind from DotcomBlinds is made to the highest standards, designed to provide you with years of service and shade.
In fact, we’re so confident and proud of our blinds, we offer a 3 year warranty on all our blinds. This is one of the longest warranties available and a clear sign of the quality of our blinds.

Obviously, there are a few exclusions:
✖ Damage caused by poor installation/not following fitting instructions (don’t worry, installation is easy, read this.)
✖ Misuse or Failing to maintain the blind
✖ General wear and tear and fading (these blinds are exposed to very intense UV rays)
✖ Alteration to the blind
✖ Exposure to the elements or fitted in an unsuitable location (these are indoor blinds!)

However, if your blind stops functioning for any reasons other than those listed above, get in touch. Our warranty covers:
Manufacturing defects
Fabric/slat colour fading within a year
Mechanical malfunction
2 year warranty on battery and mains electric motors used in electric roller blinds

So, in summary, avoid grossly mistreating your blind, show it a little TLC every so often and don’t use it in ways it wasn’t intended. If you do all those things and something goes wrong with the blind, you’re golden – we’ve got you covered and we’ll and repair or replace it free of charge.

This blind uses a chain mechanism for its operation. By moving the chain, you can lift the blind fabric up, or lower it. Our chain mechanisms are child-safe and should always be installed with any additional safety accessories provided such as P clips.

This blind features a fire-retardant fabric, providing peace of mind and safety to your home. Our fire retardant fabric is a high-quality material that will not catch fire when presented with a flame; instead, the area that is in contact with the flame will burn but it will self-extinguish once the source of heat has been removed.

This blind is made in the UK in one of DotcomBlinds’ UK factories. By purchasing a blind made right here in the UK you are helping to support the British manufacturing industry. Blinds made in the UK will typically have shorter lead times due to the fact they won’t need to be shipped internationally.

This blind is available on our Same Day Priority Dispatch Service, which is ideal for when you need a blind in a hurry. By selecting the Same Day Priority Dispatch option at checkout, your blind will jump to the front of our production queue, being made and dispatched that same day when ordered before 11am on weekdays (orders after 11 am or on weekends/bank holidays will be prioritised for the next working day). Please be aware that while most SDPDs are delivered the next working day, we do not guarantee next-day delivery.

This blind features a plain fabric with a solid colour. Plain fabrics are incredibly versatile and can easily be matched to the existing decor in your home or add a fresh new colour to your windows. Be sure to order FREE fabric samples to get a feel for the look and feel of the fabric in person before making a purchase.

This blind is available to order with a stylish headbox, covering the top of the blind and its mechanism. The use of a headbox can make your blind look neater and help to minimise light leakage over the top of the blind.

This blind features a blackout fabric, proving the light-blocking benefits you would expect from a blackout blind. This fabric will not allow exterior light to pass through it, helping to create a dark environment in your home, which is ideal for bedrooms and home cinemas. Please be aware a minimal amount of light may still leak into a room around the edges of the blind.

This blind features a thick thermal fabric, which will help provide additional insulation to your home’s windows, making your home more thermally efficient. In winter, these blinds will keep your home warmer by minimising heat loss through your windows, and in summer, they will keep your home cooler by minimising the amount of outside heat that enters your interiors.


We're excited to hear your thoughts on this product, but it looks like no one has shared their review yet. Be the first one to share your thoughts.

PRE-SALE PRICE* - £ 0 - You save £ 0

Highstreet Price Comparison

Our highstreet price comparison calculator works on an average price based on similar made-to-measure blinds sold by highstreet retailers. We compare their blinds to ours using the same measurements, same type of fabric and same mechanism, doing our best to find a like-for-like system. To find out more, click here.