I hope that this post doesn't sound like I am trying to teach your Granny to suck eggs! - But it is aimed at anyone who may have walked past those piles of fabulous embroidered vintage linens at a flea market, because they looked a little sad and grey, or yellowed with age.
I recently purchased several pieces of hand crochet work and yellowed linens. (Hope that shows in the photo.) They can be rescued very easily and bought back to their original glistening white.
Bring half a large saucepan of water up to the boil. (I use this old enamelware casserole pan for the job.) Then when it is at a rolling boil, turn down the heat for a moment and add a washing powder tablet. It will fizz, so take care that it doesn't boil over. When it has calmed down, turn the heat back up and add the vintage textiles. You need to keep it boiling, as this is what will lift out the discolourations.
It should only need to boil for about 5 minutes and you will be able to see the transformation. Remove the items from the pan and rinse in cold water.
This method will sometimes work to remove stains from the colourful embroidered tablecloths of the 1950's. I am not suggesting that you should try this with anything precious or antique, but it is worth trying on a vintage item that you are ashamed to use, as it looks dingy; it may just rescue it from it's embarrassment. Or try the ones that can be picked up for pennies at car boot sales, because they have tea stains....
They deserve a second chance!
UPDATE: Sunday pm.
I have had several comments from my American friends, who do not know what I mean when I say washing powder tablets. You could use a spoonful of washing powder instead - The sort for the laundry, not the dishwasher. But PLEASE don't try it on anything precious, just cottons and linens that you would have otherwise discarded.
Hope this helps, Niki. x