While groundsheet protectors for inner tents are not strictly necessary, they do provide some advantages. Obviously they provide a layer of protection for the groundsheet and keep it clean. They also provide a layer of insulation.
This is useful with thin groundsheet material like Chikara. In conditions of heavy dew, moisture can form on the inside of the groundsheet especially under mats and stuff sacks. One way of avoiding this is to use a groundsheet protector.
I’ve found using an Adventure Medical Kits Emergency Blanket particularly effective. Unlike old style emergency blankets, it’s silent and quite tough, like strong polythene. The silver reflective side helps insulation and, in most cases, eliminates dew.
Yesterday I cut a survival blanket to make a groundsheet protector for my OookStar. It’s very easy to cut neatly with sharp scissors. I put some small strips of duct tape at the front to aid alignment. The protector weighs 55g in all, which is a small penalty for extra protection and comfort.
blogpackinglight 
Nice idea.
I will use that I think.
Might even make a porch groundsheet.
Probably not quite as robust as double glazing film but no noise and is reflective.
What an excellent idea. I have been looking for something to use under the Chikara floor of my Duomid Oooknest. Do you think it would be possible to put in any form of attachment, e.g., with any combination of tape, grommet, shock cord?
Easy to reinforce with some tape, but don’t put under too much strain as it does stretch. I use a piece under my Duomid OookNest with no attachments and it’s fine. Also use it under my Scarp.
I use a piece of B&Q double glazing film for my porch groundsheet. Quite tough and weighs about 50g.
That’s fine for a porch groundsheet but this is better for a groundsheet protector as it’s heat reflective. Definitely makes a difference.
I have never used a groundsheet protector!
Chikara is very thin and condensation can be an issue. Small wt penalty
Have you had issues with silnylon groundsheets and condensation?
Occasionally but the silnylon in the Scarp is a bit thicker than Chikara, which is like paper. An emergency blanket footprint is so light that I normally use one.