Could you elaborate on your toning methods with tannic and gallic acids. What alkali do you use to hydrolyse the cyanotype? How do you use the acids? Do you use the traditional or the Ware recipe? The images of yours at http://www.fotocommunity.de/pc/pc/display/1985944 show a nice variation of colours. My only experimentation has involved hydrolysing with ammonia and redeveloping in tea or tannin. In both occassions the paper badly stained and the dmax was much lower than the original cyanotype resulting in a low contrast muddy print.