Good quality ready to wear garments will often have an invisible zip fitted.  These zippers are often neglected by the home dressmaker which is a great pity because they can ensure success every time. 
Invisible zips are suitable for all fabrics from fine silk jersey through to suit weight wool's and tweeds, once fitted they will be virtually invisible and will merely look like part of the seam.
The concealed zipper foot is essential if you want to fit these zips successfully and have that professional finish.