The phrase "laid on thick" refers to someone overdoing something, such as praise or flattery, to the point of being insincere or cloying. Antonyms for this phrase could include "understated," "subtle," or "moderate." These words imply a level of restraint and avoidance of excessiveness, making the message or compliment more genuine and meaningful. Other antonyms could include "reserved," "restrained," or "conservative" as they suggest a level of modesty and proper expression. Using these antonyms can help to create a more balanced and authentic communication style, without coming across as overly dramatic or untruthful.