| Answer | Crossword Clue |
|---|---|
| smutching | a dark stain smudge |
| soilure | a stain or smudge |
| soilures | SOILURE, a stain or smudge |
| methylthionine | as in methylthionine chloride, a dark green dye used as a stain, antiseptic etc |
| methylthionines | METHYLTHIONINE, as in methylthionine chloride, a dark green dye used as a stain, antiseptic etc |
| haematein | a dark purple crystalline substance obtained from logwood and used as an indicator and biological stain also HEMATEIN |
| haemateins | HAEMATEIN, a dark purple crystalline substance obtained from logwood and used as an indicator and biological stain also HEMATEIN |
