After much faffing and unsuccessful soaking I worked out a way to unblock a blocked isograph nib: Take it to bits as shown in photo. The black butt bit that connects to the cartridge can be unscrewed with a flat head screwdriver. You then remove the nib inner with tweezers. You will find the rear of the metal holder of the nib inner just inside. See other photo. Carefully and extremely gently, wipe off any stuck ink from nib inner (The needle like bit). A steady hand required. After rinsing in hot water, and scrubbing with a toothbrush and hot soapy water, blow into the main nib outer (after carefully extracting the nib inner with tweezers) as hard as possible to dislodge stuck ink in the nib. I also dunked the outer in boiling water but this doesn't seem to have been a great idea as it has warped fractionally. Then very carefully put nib inner into nib outer slowly and gently finding the hole in the centre. Add the other bits. Load up the cartridge and lock and load. If all's gone to plan the ink should flow.

The screwdriver bits in my toolbox come in little plastic holders that keep them organized. Because #2 Philips is the most popular type of screw, it comes with a whole bunch of #2 Philips bits. It's incredible just how grimy things get--it's quite a mercy that we don't notice it with the naked eye. Taken with a Nikon-mount Vivitar 80-200/4.5 macro, using a set of Nikon extension tubes. IMG_7365