The following comment regarding illustrated cards from a 1965 Catholic manners book gives one pause:
"Such cards may properly be sent at Christmas, Easter, Valentine's Day and birthdays. For any other occasion, and under any other circumstances, a card is not correct. A personal note is always to be preferred. This distinction applies even to 'Get-well' messages. . . . The use of a 'thank-you' card of any kind is never proper. . . If you have any occasion to say 'thank you,' say it yourself, in your own handwriting, on your own writing paper."
Fenner, American Catholic Etiquette (1965), The Newman Press, pp. 141-142.