A double layer of gel coat is applied to the surface of the mould.
Gel coat is available in a variety of colours, but in this instance, a grey-coloured primer gel is being used as the products are sprayed and baked when finished.
Whilst the gel coat is the first material applied to the surface of the mould, which is then backed up with layers of chopped strand mat, it then becomes the outer surface once the product is released, and hence this is the surface seen on completion.
Therefore it is important not to have any contamination, to try to ensure an even spread, and to ensure no areas are missed.