Hi both and thank you so much for your help
I think I have gotten rid of the size or anything which would've been on the fabric when I bought it, I washed it in the machine with a small amount of detergent so hopefully that will have done the job. It's good to know that you use paint directly onto fabric sucessfully
With the fabric medium, I use a Liquitex fabric medium occasionally but not all of the time, presumably this does a similar job to the Golden stuff?
I must admit I don't mind if the fabric goes a bit hard as I make wall hangings rather than clothing or anything that needs to be used or washed, so I don't mix in the fabric medium all of the time.
Thank you both again