I could put it down to weeks in the Egyptian desert but I would like to find a solution to this or at least a remedy to lessen the effect.
I have tried Testors Dull Coat, GW Purity Seal and Humrol Matt Varnish and all at one time or another seem to have the same effect so this "frosting" does not seem limited to one brand and none of my research seem to have a clear answer despite many people experiencing the same issue.
Advice prior to spraying seems to come in a varienty of guises.
1. Warm the figures prior to spraying.
2. Warm the can.
3. Shake the can vigorously at least 5 minutes.
4. Spray at room temperature.
5. Spray far away
6. Spray lightly
7. Spray a few at a time
Ditch spraying and revert to Brush on Varnish.
I am tempted to try Krylon Matte Finish (if I can get hold of it in the UK?) or Army Painter Anti Shine Matt Varnish to see if they deliver a better result.
This appears to be a popular solution but in this case had little or know effect on the colouring, it did start to lose the depth of the figure. I suspect though this is due to the lack of actual casting depth in the plastic model.
2. Apply a coat of Thinner or Nail varnish remover.
This did not work, I applied it with a cotton bud and rubbed the effected area, it dried only to return the same effect as before.
3. Apply a brush coat of Matt Varnish.
This had the impact of dulling the effected area but the colour still suffered some discolouration.
4. Apply a brush coat of Gloss Varnish.
Having never been a fan of this type of finish, I need to pay a visit to the habby store for a can of this, it appears reading other blogs and forums that this has a mixed impact working for some but not for others.
5. Apply a ink wash over the figure to lessen the effect.
This did lessen the efect and was easy to apply given the type of figures effected, but I can see this being a problem for more detailed figures or where the desired effect is for bright uniforms, such as the Napoleonic Period.
6. Apply a coat of Olive Oil
You will need to do this to also remove the excess oil.
Could Olive Oil is a solution that has plagued wargamers for several years.... Try it for yourself.