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A technique has been developed to produce miniature, high-density capsules of curium-244 oxide contained in three concentric jackets of metallic gold or silver. The final capsules are right circular cylinders, 6.350 mm diameter by (3.18±0.05) mm long, with a minimum density of 11.0 g/cm 3 . Each level of containment was soldered or brazed closed, with the outer surface free of detectable alpha contamination. Fabrication was performed in three separate small cells operated by standard master-slave manipulators. Production capsules have been stored for up to five years without indication of dimensional growth or leakage of radioactive contents. The dimensional stability of the capsules is attributed to the microporous structure of the plated-gold structure which permits helium gas resulting from alpha decay to diffuse through the capsule wall while retaining all radioactive materials.