Because official production is currently limited or paused for rebranding, your best options for finding remaining stock are through third-party marketplaces and specialized craft stores:
Finding has become increasingly difficult as the brand’s parent company, Crafter’s Companion , is currently in a state of transition regarding its ink products. While the markers themselves are widely available, the official 30ml refill bottles are no longer listed on the manufacturer's website and are being phased out by major retailers. Where to Buy Spectrum Noir Refills where to buy spectrum noir refills