My department, the Training Team, goes through a lot stationery supplies, including flipchart markers. Sometimes it's hard to find reliable markers that do not bleed through the flipchart paper or run out quickly. I think we've finally found a brand that we can count on - Staedtler Lumocolor flipchart markers.
They come in a package of 6 colors: Red, Blue, Purple, Green, Orange and Black. The tip is rounded and 2mm in length. The ink will not bleed through paper which is great because this prevents wasted flipchart paper. The colours are bright and brilliant. The flipchart markers are also dry safe. This means that they can be left uncapped for days without drying up. This is also a great feature of the flipchart markers as sometimes participants will not put the caps back on the markers properly. They are also refillable. I've never heard of any other company selling refillable flipchart markers, refillable pens and mechanical pencils maybe but not flipchart markers!
They also come in a unique clear plastic case which doubles as a stand making the markers easy to grab from a flat surface like a desk. They are made in Germany. All in all this was a great purchase. I highly recommend the Staedtler Lumocolor Flipchart Markers!