Organisations and businesses in the town are being approached for financial assistance and ideas are being sought as to what the mural should be.
An old mural which had become faded has been painted over and permission has been granted for a new one on the side of the new DIY store.
RSPCA volunteer Sue Wallace said: 'We have had some offers of help with things like scaffolding but we need a few hundred pounds to do the work.
'If there are any artists out there who would like to get involved we want to hear from them too.
'There are quite a few shops in Taylor Square and Market Street and we would like love to attract more people to this area.'
Anyone who wants to get involved should call Mrs Wallace on 01822 615335.