Yes we could encapsulate… the question becomes interference from the body. UHF backscatter is much more susceptible to signal killing interference from salty water (human body). Stick some tags you want to try onto your arm and tape over them and test performance. To make it even more accurate, fill a polymer bag with dark brown sugar and flatten it down to a layer that is at least 2mm thick. Then place that overtop the tag and tape it down and test again. Brown sugar is commonly used in RF testing as a human tissue analog and it’s less messy than raw meat.