Question:
Is a person allowed to walk around with stains on his clothes or is that a chillul hashem
Answer:
A Jew should always look presentable and respectable, because we represent the people who Hashem choose to give His Torah. This is a one the reasons that a Jew may not make cuts and desecrate his body, (see Rashi Devarim 14-1). However for someone whose profession is such, (i.e. a painter, mechanic, plumber, etc.) they may walk around that way.
