In the Gorey, Co. Wexford Byrnes on the main street stock art materials but I find the range limited and expensive, try the Bookstation down the road, Tesco and Lidil (when they are running art material promotions) offer good value in art supplies. All these places sell off craft supplies and bits and pieces to clear stock and make way for new products coming in. So if your around the town drop in and check what's on offer.
If your looking for an art shop near you check out your local http://www.mykidstime.ie/ for listings.
These are the places I recommend and purchase from
Premier Arts and Crafts, Greystones or Bray, Wicklow. For contact details http://www.premierartsandcraft.ie/ no online shop. Both shops in Bray and Greystones are excellent. They also stock great craft fun stuff for boys and girls that are excellent value and make good gifts.
Hopkins Toymasters, Wicklow Town. Established since 1850 so there is no building number you will find them in the middle of the main street, car parking for customers to the rear. Great shop worth a detour from the N11 or a trip all by itself. Toys, books, stationary, great craft and art supplies. They offer great value and will order products for you. Very friendly.
Evans, Dublin for map and address http://www.kmevans.com/ no online shop which is a shame but an excellent shop & they will deliver. They offer great value. I used to go there as an art student and still go there as an artist and teacher.
http://www.corkartsupplies.com/ good online shop. If your unable to get to an art shop and need supplies, have access to the internet and have a credit card this is the place for you. If you don't have a credit card you should check out 3V as an option for online payments. If you go to Cork make sure you check this shop our its great.
http://www.craftsupplies.ie/ Great little site. if you never buy anything from the site go look at the buttons - so cute, so cool!