Abstract: An apparatus and method for controlling the size and shape of a shrink film envelope around an article or a package to prevent the formation of wrinkles and bunching of the film when it shrinks. The apparatus comprises a hot air shrink tunnel having a conveyor for moving the article on packages through the tunnel. An assembly is position within the tunnel a preadjusted distance away from the article forming a fixed boundary to which the film envelope expands and is restricted, causing the air within the film envelope to be directed to areas around the article to keep the film from touching the article until the film shrinks. The assembly comprises material of low thermal conductivity such as a plurality of wooden wheels for contacting the film envelope.