Two big exhibits up now, The Boston — Jo’Burg Connection: Collaboration and Exchange at Artist Proof Studio, 1983-2012 and reThink INK: 25 Year at Mixit Print Studio celebrate what a collaborative process printmaking is, and how it fosters and builds community. “The Boston –Jo’Burg Connection,” at Tufts University Art Gallery, is the far more successful show. It tells the story of Artist Proof Studio in Johannesburg, which was founded by Kim Berman, a South African who lived and studied in Boston and has subsequently brought many Boston printmakers to Johannesburg to mentor and collaborate with the Artist Proof artists. Over nearly 30 years, those artists have used printmaking to bridge the racial divide forged by apartheid, to cope with the AIDS pandemic, and to learn how to be standup artist/citizens. The work in the show – several portfolios, team-made linocuts, and other works, such as Berman’s “Telling the Story,” two documentary prints (one is above), convey the growth and scope of Artist Proof. “ReThink INK” marks the 25th anniversary of one of the Boston area’s most prolific and impressive print studios. The problem with the exhibit is that it has no shape, no story, no through-line. There are many worthy artists in the show, but the installation doesn’t support their work. Even the 66-print portfolio made to commemorate the anniversary is all over the place — nothing holds it together, thematically or visually. The moral seems to be: If you’re going to mount a show, tell a story or make an argument with it. A party is just not enough.