As far as the matt black paint being removable while the primer was not goes, thats how things are supposed to go down
Primers are supposed to adhere really well to surfaces that are not ideal for the paint itself to adhere to (primers still dont stick to glossy un-prepped surfaces though and will peel/flake away from a poor surface,fortunatly, bare polystyrene plastic isnt overly glossy, it does lack tooth though, and we overcome this problem not by sanding it, but by having the solvent within the primer/paint act as an etching agent - this is why it is said that good primers stain plastics... because they actually do.)
And then the surface of the primer gives a good low sheen and lots of tooth for the paint to stick to.
Now I get what youre saying, that removable is a bit of a plus, as i've also stripped and repainted many figures, got some orks in the process right now.
Halfords Matt black spray was easier to remove than army painter primer. But that was the only real noticable difference for me. In terms of the actual spraying ,both worked totally fine, with no gunking of detail, a very flat, black finish on both, good amount of tooth for taking the next layer of paint on both, Dry time perhaps was quicker on Halfords one, but not by enough to be bothered about it.
I see a lot of threads here about their army painter going on a bit fuzzy where theyve sprayed it in less than optimal conditions, or at an incorrect distance from the job.
Would imagine any spray will do that given the same bad conditions and usage, You want to be laying down a really thin dusty coat first up, and allowing it to half dry (known as a tack coat), then before the tack coat drys (hence while its tacky) lay down a wet coat aiming for coverage here, Only do one coat here, and let it dry completely, if you missed a bit, tough gak! you need to wait for the rest to dry now before adding another layer. Its really easy to get ahead of yourself and blast a mini all around giving total coverage in one single thick blobby coat. which is the wrong way to operate the paint can.
Its the patience of waiting between coats and not going too heavy all in one go that leads to a superior spray job no mater what product is being sprayed.
If you lay it down too thickly and go for second coats too soon it will likely lead to something called 'solvent popping' where the lower layer's solvent becomes trapped by the new layer and can do a variety of funny things to your paint.
Which would be the opposite of laying it down too dry, having the can too far from the job (distance varies with temperature, humidty, wind conditions etc) which is known as 'dry-spray' or 'over spray' this ones fairly common among wargamers as far i can tell.
The other most common paint defect is known as 'orange peel' and comes from paint being too thick in the gun/can, and being applied with too little presusre. The surface of the paint takes on the dimpled effect seen on some fruit such as orange peel funnily enough
If your getting this, warming the paint and shaking the can a lot may solve it, if not your can might be about to run out of pressure but not paint (meaning it was overfilled with paint)
If weather conditions are questionable, or the primer is one youve not tested before, I suggest trying it on sprue first, or some model your not fussed about ruining (just on the offchance the primer is unsuitable)
) than some of the others. Never had any issues with it. I did have an issue with the spray PRIMER which I couldn't remove hence why I will always recommend the paint instead of the primer.
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