Reasons
Ever wonder why the paint comes off the car but sometimes the lettering remains? Especially gold and silver.
It has to do with the process by which the cars are painted and lettered. Most model railroad cars are painted by an automated spray process. The paint that is used is a quick-dry semi- flat enamel. Most any mild solvent such as brake fluid will remove it.
The lettering is a different story.....It's not paint but rather an ink that is applied by a pad printing process. To make it simple its sorta like a high speed rubber stamp. The ink tends to bond tightly to the car body itself as it actually penetrates the layer of paint that has already been sprayed on.
Now to gold and silver....these inks have to be applied with what is know as a hot stamp process because of their metallic content.
The heat causes the ink to penetrate the paint and bond tightly to the carbody. If you look closely after you finally get gold or silver letters removed and you can still see their outlines due to the tight bond that was made by the hot ink.
Just another tid-bit from The Robber Barron's Vault of Useless Knowledge...Brought to you by BUFFALO CHIPS...THE BREAKFAST OF CHAMPIONS!!!