I am trying to add my own button/icon images and I think I must be uploading them to the wrong directory?

I found the button I wanted to change in
includes/templates/template_default/buttons/english/add_to_cart_button

I made a new button the same size and uploaded it to
includes/templates/custom/buttons/english/add_to_cart_button
but it didnt work
soooo

I uploaded it to includes/templates/template_default/buttons/english/custom/add_to_cart_button

still didnt work

any idea what I am doing wrong?

Thanks