I continue with questions...Please, help!

I have a doubt, I´m in love with a vintage pattern model is available online.
I´m able to make the patterns of any model that I see a photo or elsewhere, the question is...
It is illegal that I to do these pattern for me without buying it?
Clearly, I´m not going to trade with it, I want to become the model for me only, but I have doubts whether this is illegal....
Thanks to all for help me.

Paola