Merida has become a destination for artists and art lovers over the past decade. Every year in the winter there is a benefit tour of artists studios and you can watch Allison Wattie´s blog for the details as she organizes it. There is a Noche Blanca twice a year on the summer solstice and one in the winter (google is your friend). An evening when the galleries are open and there are special events in the parks and theaters. Many artists open their studios for the white evenings. The Mayor´s office publishes a map and there are buses that make all the stops in the historic center.
If you are visiting at another time of year it´s still possible to visit artist in their studios. Many local artists have their own website or have a page on Facebook. Otherwise you can visit the galleries and if you see something you like they can arrange a studio visit.