I am thinking of pulling together small sets of my handmade cards that I will offer on my Etsy store. What I have in mind are cards that might not be easy to find such as the pro Palestine one here. Cards on the side of fairness, kindness, anti-bigotry and overall fun cards as well.
Handmade cards are labor intensive and thus costly. Most solo card makers invest a lot of money to produce these small, popular handicrafts. And there is definitely a craft to card making.
I hope that someday handwritten correspondence makes a comeback. Personally, I have always loved writing and receiving letters from loved ones; and it's something I hope to do all of my days. These days people communicate with the use of technology and often bypass tangible handcrafts. But I do think handmade cards will always remain a niche market because there's nothing like receiving a small handicraft with a loving message that you can display on your counter, over your desk, etc
