I have to convert my small postage sizsed back lawn to a patio for wheelchair access reasons. I liked the look of Bradstone panache silver grey ground slabs but the only review I can find is one on Band Q website and the reviewer said she found that glazed pots leaves rusty coloured non removable marks on the (black version)slabs. Have any of you out there any experience with these slabs?. I just cant afford to waste any money if I lay them and they get marked easily. Thanks.