When describing someone's facial expression, "mask-like" can be an effective way to convey a lack of emotion or a fake persona. However, using synonyms for "mask-like" can bring a more nuanced and vivid description to the table. Such synonyms include "expressionless," "stoic," "poker-faced," "blank," "emotionless," "inscrutable," "unsmiling," "rigid," "impassive," "wooden," and "unreadable." Each of these words brings a slightly different flavor of emotionlessness to the subject's expression, and selecting the right one can add depth to your writing. Whether you're crafting a fiction piece or a news story, experimenting with synonyms can make your writing more interesting and engaging.