Permanent adhesives are most often used for thermal transfer labels. They are usually very strong and will break if you try to take them off. They range from strong adhesives, designed for general-purpose labels, to ultra-aggressive adhesives required for very rough surfaces (powder-coated, angled, textured metals, etc.). Permanent adhesives can be acrylic-based, rubber-based or latex. Some of the best solutions are: general purpose permanent rubber based adhesive that offers high initial tact, permanent acrylic adhesive that provides excellent adhesion on a wide range of materials in different temperatures, low cost permanent latex adhesive for general labeling, etc.
