Heat-seal blisters are still a large portion of Shepherd's production, although clamshells have grown in popularity in the last 10 years. While blister packaging is inexpensive it does require a heat-seal packaging machine. These machines are available in simple shuttle formats or high-speed carousel lines with automatic blister, card and product feed. Shepherd can help with the selection of this equipment and recommend the proper blister card material and adhesive. Shepherd has 25 years experience in blister packaging. It is important to understand the heat-seal process and the effect that heat-sealing has on the blisters if they are not formed using the correct time and temperature.