I recently found an old heavy weight dan grade Do Balk at home that must be about 10 years old, It had all the badges, midnight blue trim and writing on it (they usually cost us about £100) It was in good condition but gruby and yellowy stained. I soaked it over night in 'Biotex' (that's what its called in the UK) it's a bleach free whitener so can be used with colours. I washed it after and it was like new.
