General Information on Printing for Magazine Article

Hi folks. I am not a printer but am writing a magazine article on the printing of murals for wallpaper. You may have seen the cheaper $99 murals of palm tree sunsets at Home Depot printed on very thin stock...maybe 24lb?

My question: Do you think that these are printed using 4 color offset machinery, gravure, or what? I have called several companies who make these scenic murals and they block me with "we have a proprietary process." As if this is a state secret;-)

Also if you take at stab this one: Wallpaper installers use pre-mixed modified starch based adhesives which may contain different ingredients. Some of these adhsives contain ammonia which , in my experience, will remove water -based paint. Do you think ammonia (or some other ingredients) would remove water based inks more readily than solvent based inks? Thanks in advance for any info. I appreciate it.