Micro Set is the mild one, and Micro Sol supposedly the more aggresive one…I use the first one but not the Micro Sol, as I find Solvaset a better, more aggresive choice (and also less expensive).
At the risk of boring those capable of doing good decal work, I’ll include my procedure for applying decals:
First, I would suggest that you wash the car (or locomotive, structure, etc.), using warm water and dish detergent, then rinse it thoroughly with water and let it air-dry.
Once it’s dry, airbrush it in an appropriate colour(s), then set it aside to let the paint dry/cure/harden, depending on the type of paint you use.
Once that is done, airbrush the entire areas which will be decalled with Glosscote (or your preferred clear gloss) then let it fully dry until there’s no odour of solvent present on the car. Don’t apply the gloss only where the decals will be applied - for rolling stock and locomotives, those areas are usually the sides and ends - cover them completely with the gloss, even if the amount of decal work will be very minimal. Allow the clear coat to fully cure/harden - there should be no noticeable odour to it, (this minimises the chance of the setting solutions reacting with the clear coat).
Next, use a sharp blade to cut the needed decals from the sheet, keeping as far away from the lettering as possible. Once you have all of the required lettering free of the main sheet, use a sharp blade (re-sharpen or replace as necessary) and working on a hard surface (I use a sheet of glass on my work desk for this), to trim away as much of the blank paper from as close as you can maneuver the blade to the lettering, using a straight down chopping motion, rather than slicing it away. If necessary, do this work under magnification (eyeglasses, Optivisor, or loupe).
The reason for the two-part cutting is that slicing the image, even with a sharp blade, raises the edges along the cut line, and whe