Convatec Duoderm Cgf Sterile Dressing. CGF dressing is a hydrocolloid, moisture-retentive wound dressing used for partial and full-thickness wounds with exudate. It incorporates a unique ConvaTec hydrocolloid formulation that distinguishes it from other hydrocolloid dressings. DuoDERM CGF dressing is indicated for use on dermal ulcers including full-thickness wounds, pressure ulcers (Stage II-IV), leg ulcers, superficial wounds, partial thickness burns and donor sites.