The technique used here is called Crayon Resist and I was recently reminded of it by GinaK through her Stamp TV site. If you don't visit there you should :) She has s9ome awesome tutorials and many are done with video to show you step by step. Visual is good in my book!
The stamps used come from Artful Inkables set called A Friendly Light it is a great set for by the sea themed cards.
Paper is from Hollo's and some Gumdrop Green Pop Tones from Paper Temptress. I added a wooden anchor to the corner and some ribbon from RRR to the card too.
When I was sponging on color I somehow picked up a bit of the black that I had stamped with (even though it had sat overnight to dry!) but it ended up in the sky and then looked a bit like clouds throughout so I left it :) I did notice I should of colored more evenly with my crayon on the sky to block the color from the cloud and lighthouse better though...practice practice practice I guess is the key here! LOL