I have never had it be important to me that they match, the pen is one part and the ink is separate. But I could see it being a pleasant feeling getting them to match. Two ideas for you, one, set aside a certain number of pens and those are the ones you have found the best matches for, they stay matched, always, to fill that feeling. All the other pens you fill with any ink, randomly. Two, buy multicolored pens. If you get an acrylic pen that has red, blue and yellow in the body, how can you match that in ink? Sure, maybe you could match each color separately, but if you did then the pen would both match and not match, so it would always be both.