And here we see why I don't like Tamya paints. You can see how the black (Tamya) provided by the model store as they were out of stock of Humbrol matt black as rubbed off from handling, and the yellow (Humbrol) has not. More touch ups required....
Are the Humbrol enamel, lacquer, or acrylic? Even the enamel Tamiya pains are a proprietary blend, and not straight enamels. I have switched over to all acrylics, and the strongest solvent I need now is alcohol, I keep 91% isopropyl on my desk and denatured in the shed.
I always put a dull, satin, or gloss clear coat when using Tamiya paints. I've never had a problem with them rubbing off like that. It makes me think, "Did you wash that plastic model before you started assembling it?". There may have been injection mold residue on it.
I agree. Humbrol paints are better. Tamiya is not as good a it was in the 1980's. I don't know why, but their quality has diminished. I used to use Tamiya Liquid Glue for windshields, and I used it for a Kaman Husky helicopter model. The fumes off of it clouded the glass. It destroyed a very expensive model.