Void-containing polyester shrink film with improved density retention

A process for making a void-containing shrink film, the process comprising steps of:

• (i) mixing a copolyester and 20 to 30 weight percent of a voiding agent based on a total weight of the copolyester and voiding agent at a temperature at or above the glass transition temperature of the copolyester so as to form a uniform dispersion of the voiding agent within the copolyester;
• (ii) forming a film from the dispersion;
• (iii) orienting the film in one or more directions at a temperature above the glass transition temperature of the copolyester;
• and
• (iv) annealing the oriented film at a temperature above the orienting temperature and from about 85° C. to about 110° C.,
• wherein after 5 seconds in a 95° C. water bath the annealed film has a shrinkage of at least 40%, and
• wherein after 15 minutes in a 85° C. water bath the annealed film has a density of less than 1.05 g/cc so as to float in a recycling process wash bath having a density of about 1.03-1.05 g/cc.