These two heat press options are the most common choices in the sublimation industry, as they are the most affordable options available. Each has its own advantages and disadvantages to consider.
The clamshell-style press is typically the least expensive press option in the industry. But don’t let the price tag fool you. I have seen clamshell presses in shops that have been used for more than 20 years and are still going strong. These presses typically have the best thread-ability (you can quickly load and unload a T-shirt) and they also tend to be easy to operate. Because the heat platen lifts from the base, no additional space is needed to operate the machine outside of where it sits and the space for you to do the work. Some other positives are that these units can typically be equipped with an auto release mechanism. The drawback to a clamshell-style unit is the fact that the heat platen is directly above you and if you aren’t careful, you could burn the back of your hands, especially if you are working toward the back of the machine where the heat platen is closest to the base. Also, it can be difficult to layout projects with transfer paper because it has a tendency to curl from the heat above it.
The swing-away-style press is slightly more expensive, but they also are well-built presses that can provide a wide range options and years of use. These presses give you the ability to press thicker items like awards and plaques as well as provide a much easier surface to layout trickier garments like polos, button-down jerseys, etc. These styles also move the heat platen out away from the base, which provides a much safer environment for laying out your heat pressing project. This style press works well for heat transfer paper, multi-layer vinyl projects, rhinestone transfers and mixed media projects. The drawback to the swing-away press is the need for a larger work space for the heat platen to swing away. You also have further to reach to get the heat platen back and forth.
-Aaron Montgomery, 2 Regular Guys, MontCo Consulting