Need Advice

Hi all I am making a safety rope to tether my harness to the tree when I am in a deer stand. My question is what is the smallest diameter rope that is safe to use? The smaller the better because I have limited room in my pack. However, I obviously want the rope to be more than capable of holding my weight in case of a fall. Any suggestions on a specific rope would be much appreciated. Thanks

Welcome to the forum
Slings may be a better option for you, very strong and take up less space than rope
You can take a few different sizes and join them together if you need to
Are you using the tether for positioning or fall arrest?