I have bought it some time ago on ebay for about $12 for 10ml tube (with free international delivery). It is a photosensitive liquid that you spread over the board, let it dry and then put a film with the solder mask image over it and put it under a strong light for some time. Finally, you develop it with a gasoline or oil based solvent.
Search for "UV solder mask" on ebay. It will give you about 8 results.
I didn't have a chance to try it yet, so I cannot tell you how well it works, but the sellers on ebay have a guide right on the product description page showing some photos.
Thanks,
Jan
--- In Homebrew_PCBs@yahoogroups.com, "pjbuser" <pjbuser@...> wrote:
>
> Hi Can anybody help on where I can buy green solder mask from
> Have searched everywhere
> Or if there is an alternative product that is green I could use
>
> Hope someone can help
>
> Thankyou
>
> Paul
>