| Yes you can get semi gloss clear, Tamiya do an acrylic one.
You see the edge of the decal because it is not completely adhered to the surface. The slivering is actually air inderneath the film making it show up.
Have a practise on some scraps before comitting to the model. Prepare a couple of samples that have been created with exactly the same process as your model then see what happens with some of your ideas.
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“Dirty British coaster with a salt-caked smoke stack, Butting through the Channel in the mad March days" | 
Linear Mode
