Analysis of information sources in references of the Wikipedia article "Ventile" in English language version.
[F]rom 1951, the Mk 7 onwards was made from ventile fabric, invented by the Shirley Institute just post war. [I]t was woven from Egyptian cotton in [a way that] would allow body moisture (i.e. water vapour) to pass through the interstices of the fabric, yet when immersed, the cotton fibres would swell to produce a waterproof garment. [S]uits had to be made from two layers of fabric to prevent the hydrostatic force of the water pushing its way through a single layer of fabric before the fabric had time to swell (Reference 172). Other disappointments were that it was very expensive to manufacture, expensive and labour intensive to construct the suits, and the fibres would not swell effectively when exposed to body sweat or greases.
[F]rom 1951, the Mk 7 onwards was made from ventile fabric, invented by the Shirley Institute just post war. [I]t was woven from Egyptian cotton in [a way that] would allow body moisture (i.e. water vapour) to pass through the interstices of the fabric, yet when immersed, the cotton fibres would swell to produce a waterproof garment. [S]uits had to be made from two layers of fabric to prevent the hydrostatic force of the water pushing its way through a single layer of fabric before the fabric had time to swell (Reference 172). Other disappointments were that it was very expensive to manufacture, expensive and labour intensive to construct the suits, and the fibres would not swell effectively when exposed to body sweat or greases.
