Material List - Need or Need Not?

Should my patterns and instructions come with a Material List?

I've always suggest my customers to refer to the first step of every instruction for guide on the fabrics required for the projects.

Sometimes you might need a lot of brown but only a small piece of red fabric which you still have remain from your previous projects. If I were to put Brown felt x 3, Red felt x 1, customers might buy a whole piece of the red fabric only to realize that they only need a tiny bit which they have left overs from their previous projects.

Also the sizes of felt each individual uses are different, as for me, I use a 23" x 23" felt and some use A4 and others B5 size.

I'd welcome your comments and suggestions. If you have one, please feel free to email me at litlbrownbird@gmail.com.