Thanks Mike, but none of those suggestions will help. The current product is just sub-standard garbage, from the quality of the tins, to the consistency, or lack of it, in the quality, shade, hue and finish of the paints. As I mentioned, I've been using this brand for almost 50 years, without problems, until the recent change - which, incidentally, was after legislation regarding additives etc.
Wherever it is now produced, and I suspect it's in some sweat shop in India or China, at the cheapest possible rate, it is done so under non- existent QC systems, or the producers just don't give a monkey's. It should not take a week for a paint to only partly dry, leaving a sticky film on the surface! And that's only one of a number of problems.
As mentioned, I've used the product for so long, both in modelling, and in artwork, and in large quantity, that I know (or knew) by instinct exactly how to achieve certain mixes, shades, effects, results etc - things I can still achieve with other, quality paints. With the current Humbrol product, I wonder each time I open a tin, what the result will be!
As an example of the terrible quality, I have two tins of the same colour, bought at the same time - one is like partly set gum and will not 'stir out', whilst the other is like water and pools to translucence if used. And yes, I have tried adding one to the other!