Your first big decision when choosing a Polytunnel is almost always..."What size is ideal?". But there's other important factors to take into consideration..."What type of cover do I want?". It might not sound like something to give a lot of thought to, but the cover you choose will affect your day-to-day Polytunnel management, what and how you grow. We have 4 options to choose from...

Smart White

Smart White PolytheneThis specialist film reduces light transmission to 65%, and ultimately the temperature inside the structure. This film is most useful where sun scorch is a problem for growers. It is also suitable for animal husbandry applications and other stock and storage houses where a great build up of heat is not ideal. This UV stabilised film is 180 microns (720 Gauge) and is supplied with a five year guarantee.

FOR USE WITH Animal Husbandry structures and those plants that would normally grow under a shade canopy.

Smart White Properties

bpi.visqueen is a division of British Polythene Industries plc - one of Europe's leading manufacturers of polythene film products. Their products are used by Farmers, vegetable, fruit and flower growers across the globe and are all designed to help the grower create their own 'climate for success'.

Solar Radiation

Although guaranteed for 5 years against its biggest threat of sunlight degradation, when fitted correctly, it is not uncommon to hear our polythene covers have lasted in excess of 10 years.

5 Year Polythene Guarantee

Please note - to help identify the polythene type and validate the guarantee, a series of numbers and letters are intermittently printed across the polythene.

View the terms of the Guarantee here.

Sunlight is the biggest enemy of polythene. While it's essential for the wellbeing of whatever you're growing, it also 'kills' polythene in much the same way you can find old discarded crisp packets lose their colour and become very brittle. First Tunnels polythene covers are developed and tested in the extreme conditions to give optimum performance and are UV stabilised to prevent the polythene from breaking down prematurely.

What is a KLy?

A Kilo-Langley is the measure of Solar energy radiated in 1 year. It varies from a minimum of 60 KLy in the Polar regions to 120 KLy in warm regions, and to a maximum of 200 KLy in the African desert. Southern Spain receives about 140 KLy whereas the UK receives about half of that, just 78KLy.

Solar Radiation


Our Smart White polythene is 720 gauge/180 micron and made up of 3 layers for outstanding strength and performance.

Total Transmission of Visible LightTotal Transmission of Visible Light
The amount of available light entering the polytunnel through the film. Measured as a percentage of total light.
Smart White = 65%

The scattering of direct light entering the polytunnel ensuring no shadows, so all plants receive equal light. Measured as a percentage of total light.
Smart White = N/A

Thermal EffectThermal Effect
A pocket of additives within the layers of the film that ensure and maintain a stable and optimum temperature within the polytunnel, especially during the night when it is colder.
Smart White = N/A

Strength at BreakStrength at Break
The load on a tested sample when it breaks. This is expressed in Pascals or MPa.
Smart White = MD23/TD22

Elongation at BreakElongation at Break
The strain on a tested sample when it stretches. This is also expressed in Pascals or MPa.
Smart White = MD630/TD770

As the weather changes becoming hotter or colder, so the Polythene expands and contracts. Creep is the terms used to express this.
Smart White = 5

Dart TestDart Test
A test to measure the impact strength on a test piece of plastic, using a weighted falling 'dart'.
Smart White = 700