The AK Interactive Real Colors Marker in Flat Black is an acrylic paint marker designed for model-making. It provides excellent grip on various surfaces like plastic, resin, metal, and wood, and is resistant to water and heat. The marker can be applied in layers, offering high coverage without blurring, and is safe for subsequent weathering. 

Here's a more detailed breakdown:

• Acrylic Paint: It's a paint-based marker, not just an ink marker. 
• Special Formulation: Formulated for modeling, offering a high grip and good coverage. 
• Surface Adhesion: Works well on plastic, resin, metal, and wooden surfaces. 
• Water and Heat Resistant: Durable and long-lasting. 
• Layering: Can be applied in layers like regular model paints. 
• No Blurring: Ensures clean and precise painting. 
• Weathering Safe: Allows for weathering techniques without removing the paint. 
• Versatile Use: Suitable for base coats, small-scale painting, and camouflage. 
• Finish: The marker's finish is matte, though some colors might have a slightly satin sheen due to the pigments. 
• Varnish Compatibility: Can be coated with any type of varnish without damage.