Wear & Tear - Legislation S284 TCA 1997 states:

Section 1
A trader who incurs capital expenditure on machinery or plant is entitled to a wear and tear allowance if the asset is in use for the purpose of his trade at the end of the basic period for the tax year.

Section 2
The annual wear and tear allowance is 12.5% on a straight line basis. Where a corporate or individual tax payer buys a work of art and displays it at their business premises for the purpose of promoting their business, the work of art is treated as machinery or plant, and is eligible for the annual wear and tear allowance of 12.5%.

Your accountant should be consulted with regard to all intended art related investments and where deemed necessary be approved by the Revenue Commissioners.