The article below was just a response to a thread on the “Lead adventures forum” and it went over so well there they made a page out of it so I figured I’d repeat it here since I’m asked a lot.
Hi all, I’m “new” to the site but as someone said once “I have figures older than some of the people I game with!” so I have been around the “workbench” a long time. I remember when people never coated their figures and mounted them on card stock to be stored in a used Pizza box! It would amaze me that they took the time to buy, paint, and mount the figures but the “extra” step of protection was too much! Every game day there would be another person with a “jammed on the brakes” story” and a box of chipped bent minis! While I did not invent the mounting style (at least I imagine someone did it somewhere else before me) I did “refine” it and in my neck of the woods many people now mount there figures the way I do. I have an article on mounting on my website that was written by me for the now sadly defunct “Wargamer” magazine about 10-15 years ago. I have it posted on my website you can check it out there [url]www.historicalhobbies.com[/url]. Wow have I gotten off track…lol.. I was going to comment on TESTORS Dull and Glosscoat. I have used many different finishes over the years and from experience I know that Testors is better than sliced bread! I used shellac, varnish, Krylon Matt and Gloss sprays and more, but for the last 10 years or more it’s been Testors exclusively and I have had 0 problems if used properly…. I spray my protective covers as opposed to brushing them on. I do this because many times I use several different mediums of paint on a mini, lacquer, acrylic, ect… and some of the protective covering have agents in them that will “soften” or “re animate” your paint! If your brushing this “pressure” might lead to disaster! Spraying is very gentile and everything should dry out and be fine. Also a note that “Magic Wash” which contains an Acrylic wax will “seal” the paint” to a point it does not offer the same level of protection as a gloss coat.
The 3 most important traits a “protective” sealer must have are:
1: Ability to really protect a miniature or model
2: Not be “destructive” or “appearance” changing to Mini or Model
3: To have the “Stability” to last over time without  color, clarity, or finish change!
There is a 4th consideration to I think, the cost and ease of application.
I used various “Varnishes” in the past but they are not specifically designed for application over miniatures and I have found that some tend to “yellow” with age and while this being great on boats and antique furniture stinks on your minis! So without going further this is what I do:
Once I finish painting I let mini “dry” for a day to assure there is no “wet” paint or wash left as this will cause the “white” bloom sometimes seen after coating. I use an old hairdryer to cheat! I then SPRAY coat the mini with 2 (TWO!) coats of GLOSS coat  separated by at least 1-2 hours of dry time. Let dry again, hair dryer time again if you want to cheat! Then I mount my figures and do any base paint/flock. At this point I use to Spray dull coat the figs AND flocking but I have learned a new trick. I found that basing flocks no matter how well glued and done suffered over time and if they get dusty were tuff to clean. I one day decided to try GLOSS coat the basing too! It works great! By coating the flocking or other basing material you give it protection and strength it would not normally have it also helps to glue it in place and protects it from fading! After this step has dried Dull coat to taste and you have the best looking/protected mini on the planet! The double layer of gloss coat gives a lot of added strength to the small “stick out” parts on your minis. Even though my minis are cased they do pick up dust over time and I have found that the coated mini and base can be GENTLY washed under a warm flow of tap water and GENTLY “scrubbed” with a large/soft/but sort of firm paint or make up brush “nikd” from you wife or girlfriend! Note I base on magnets or metal stock so if you STILL use card stock be careful! I then blow of excess water and dry with hairdryer. If my minis get a lot of use and the matt is wearing into the gloss I will give them a re-spray.
 
Things you don’t want to do are spray in very cold or very damp situations. This can lead to milking and coverage problems with almost any coatings. Also in high heat situations your “spray” can actually be drying some before getting to the miniature! This will produce a “frosting” effect or possibly a ruff sandy finish (happens with paint too!)
 
I used to apply my TESTORS Gloss/Dull coat from their spray cans but the spray is too heavy and the cost and trouble to find it was a pain. Long ago I stepped up to a “Badger” airbrush and it has paid for itself 100 times over in savings not to mention the added creative tool to paint with! I now buy my Testors in their 2oz bottles at about $3 US which is about $1 less than a can and goes at least 5 times as far and covers much better. I also found that I could “mix” the two, Dull and Gloss to create a semi gloss that works very well for minis that should not be “dead” flat nor “new car” gloss, I used a semi gloss my Red lacquer Samurai army!
 
USE GLOSS COAT if you want to protect your minis or model, matt coat really offers little if any real protection. Gloss coating also is a step to do when you are applying decals! It avoids the “silvering” you get by trying to apply them over “matt” finish. The silvering is the micro air bubbles trapped between the matt finish and the decal that is not tight to the finish do to the micro rough surface that gives the matt look raising up the decal. This also applies to the setting and sizing or process of using a product like “Micro Sol” to “melt or soften a decal causing it to confirm to a models uneven surface, IE rivets. If you do not have a “slick” gloss surface for the decal to “slide” across as it shrinks and dries it will “silver” and “tent” (lay over a bump not confirm to it). After the Decal has set and is dry (24 hours) re gloss area to seal in decal and then use matt or a semi gloss to taste. Your decals will look painted on!