Another great product by Tamiya:

This product will help you avoid the effect of the brightness of the film supporting the decals, known as "silvering".

It also softens the decals so you can adapt them to complicated surfaces.

To use it, just place a little bit of it on your model and then place the decal on top of it. It is served in a 10ml bottle.

Additional details for the Decal Adhesive Softener Type decal products:

Manufactured by Tamiya with reference TAM87193