For those of you who are outside of Canada, and thinking about whether you should enter or not, and whether it will cost you to send work to Canada, remember this: That it all depends on the Harmonized Code you send your work under and the description of your package. All costs coming in to Canada are yours, so it really benefits you to label your package properly. It can be done very easily.
Always ensure it is clear to Customs that the work is being submitted for an art show, that the work is not sold, that the work is on consignment. It would be extremely helpful for you if you contacted the broker for your shipping company – ie if it is Fedex or UPS etc. Tell them what you are doing, and ask them what to put on your package.
More information on the harmonized code for art coming through customs can be found here: http://www.cbsa-asfc.gc.ca/trade-commerce/tariff-tarif/2012/01-99/ch97-2012-eng.pdf
For more information or broader categories, please see the Canada Customs Agency webpage.