Chinese presses usually have the heat pad on the outside of the pad right next to the mug. This will make the pressing faster, however be careful of scorching and hot spots which are very common with this type of machine. These presses are also prone to have controller problems and heat pad malfunction so save up your money to buy a better one when this one gives up as parts are unlikely to be available.
The Sawgrass ink should give you a good black. Might call us and check the settings.
Paper can also be a factor, what type of paper are you using?