The first concept art I wish to show is from Oliver Jeffers' (one of my favourite illustrators) first animation produced by Studio AKA in 2008.
The concept artwork itself is rather simplistic, but still in his distinctive drawing style, taking reference from his pre-produced children's book with the same title 'Lost and Found'.
Lost & Found from Georgina Lloyd Parry on Vimeo.
Here you can see the whole process of making the animated film, but it also goes into the details of how they designed and developed the characters
(photo credits to Oliver Jeffers)
For more of his work (and concept work on this project) visit his website: http://www.oliverjeffers.com/projects/lost-and-found-film
To watch the full animation visit: http://www.dailymotion.com/video/xmrrbi_oliver-jeffers-lost-and-found_shortfilms Or alternatively support him and buy the DVD!