Historical clue formulations

• Trouble spots? — 2025-06-14
• Coffee rings, e.g. — 2025-06-07
• Besmirches — 2022-06-02
• Challenges for dry cleaners — 2021-07-05
• Sullies — 2020-03-12
• Dry cleaning targets — 2014-12-30
• Tarnishes — 2013-08-01
• Adds color to — 2013-07-05
• All targets — 2011-11-12
• Bad marks — 2011-09-11
• Reasons to presoak — 2010-10-16
• Deck treatments — 2010-06-22
• Discolorations — 2009-07-29
• Walnut and others — 2007-06-17
• Some are made with chocolate — 2006-02-25
• Spots — 1999-04-25
• Laundry woes — 1996-10-06
• Painter's mishaps — 1993-12-13