RSN Silk Shading: Keeping the silk clean!

 While working on my RSN Silk Shading piece, I have been super careful to keep all areas of the silk covered except the tiny part I'm embroidering at one time. You can see from the photo below that I have acid free tissue paper carefully secured all around the petal.However, I wasn't careful enough! I left a small area at the top of the petal clear so I could be sure of where I was placing my needle as it came over the top while stitching the first row on long and short shading.It isn't a large space but it was just enough that I got the silk a bit dirty from my hands. Now, I wash my hands frequently when stitching so the least amount of oil or perspiration gets on the fabric. I think I'm very careful. However, when I removed the tissue to see how the stitching I'd done looked, I could see a very slight mark on the silk just above the flower. It looks more like a shadow than a stain, and it's possible you won't be able to see it in the photo, but I could see it clearly.I'm sure that I rest the bottom of my left hand on that spot as I embroider and I've either gotten the silk dirty or slightly crushed the silk. Either way, I needed to fix it.The only way I know to get stains out of silk - if you ARE going to be able to do it at all - is rubbing alcohol. I dipped a Q-tip into the alcohol and, on a left over piece of identical silk fabric, I tested the silk to see if it would be damaged by the alcohol. I waited about 30 minutes to be 100% sure and it came out just fine.I then carefully, delicately rubbed the area that looked dirty on the embroidered piece. Looking below - even accounting for the huge difference in the light - you can see that it looks a bit better. Not perfect, but better.I am now stitching with the tissue paper over the fabric and a piece of lightweight white cotton on top of the tissue paper. I have the feeling that the tissue paper absorbed a tiny bit of the oil off my hand, but I'm not sure. I'm also careful to make sure any part of my had is resting only on tissue paper and not on the silk.It isn't easy to embroidery this way - it's a bit fussy - but it's definitely worth it to keep the silk clean!Do you have any tips or tricks about keeping your ground fabric clean when embroidering? Or about how to best clean silk if it gets slightly marked during the embroidery? Please let us know!