I have a cake to do for Friday that is going to be covered in chocolate paste rose, I the past I have been told that you can make them weeks in advance if they are stored correctly but when I looked at the ones I made a couple of weeks ago they just didn't look right
Can anyone tell me how far in advance I can make these as a have loads to do

If chocolate paste is like candy clay, I've made roses with it about 10 days ahead of time, and my only issue was the color fading (I've since learned my lesson about doing things ahead of time with wilton violet).

What do you mean by "they don't look right"? Are they drooping? Colors fading?

Storing them in an airtight container can make them a bit mushy, in my experience.