“There is no doubt either that young readers will be charmed by the full-colour illustrations by Donal Casey; they are excellent.” — Pól Ó Muirí - Irish Times: writing about the Irish-language children’s book Dhá Chluas Capaill ag Labhraí Loingseach
“Donal’s creativity, sharp sense of satire and technical skill have made the job of including this type of content much simpler than we had hoped. His contribution to the development of our magazine Work & Life has been very significant and it is a relationship we hope to continue.” — Niall Shanahan, Communications officer – Impact trade union.
"There is a warmth to Donal’s work that is engaging - a vivacity and divilish optimism that is refreshing in an age of snide cynicism." — Manchán Magan, Author and television presenter
“Donal was the cartoonist on our Irish Language course 'Enjoy Irish' (enjoyirish.ie). I recommend him highly for the quality of his work, its uniqueness, clarity and his delivery of the service required on time.” — Liam Ó Cuinneagáin, Director – Oideas Gael
“Donal Casey’s political cartoons are unique, insightful and humorous “ — Jarlath Duffy, chairman – Athlone Literary Festival
“Donal created four illustrations for CreativeBond's (creativebond.ie) My IOU to you gift voucher. He delivered the illustrations on time for a good price and I was delighted with them. I'd be very happy to recommend Donal to anyone.” — Lindsay Bond O'Neill - Director, Creative Bond - Greeting Cards.