I've been using Matsui 301 Waterbased inks (purchased from ryonet) for a while now. The transparent inks print great, dry great, etc. When I use their opaque ink on dark paper.. it prints great, but seems to remain slightly tacky..even after staying on the drying rack for a day. It's dry to the touch, but once posters are stacked for any amount of time, the paper starts to stick together. Any ideas? Or suggestions for different poster ink? Thanks!!