Thermal transfer printing produces very dark, dense images, has a longer shelf life and is more durable than direct thermal print, especially when exposed to heat and solvents. Thermal transfer can accept a wider variety of media than direct thermal printing giving the user printing flexibility. In addition, thermal printheads typically last longer than direct thermal printheads meaning long-term maintenance costs are lower.
Direct thermal printing is not as crisp as thermal transfer ribbons and direct thermal printing is more sensitive to environmental conditions such as heat and sunlight, which tends to discolor the media over time. Since a ribbon is not required, the primary benefit to using direct thermal printing over thermal transfer printing is that it is an inexpensive way to print labels.
Direct thermal paper remains chemically active after printing, so if the label needs more durability it needs to be top coated to resist UV light exposure, chemicals, and abrasion, adding another step to the process.