The generally accepted picture of budding depicts vesicles as forming from single-vesicle-buds910. Taken together with the positive budding results by Matsuoka et al.8, we expected to obtain separated COPII vesicles in incubations of GUVs with COPII proteins and GMP-PNP. Because COPII vesicles are below optical resolution, we expected a hazy fluorescence background in the space outside the mother liposomes. This was not observed. Instead, prominent straight and rigid extensions were formed (Fig. 2b, Movie S2). Some GUVs appeared fully tubulated. Others were densely covered with COPII-coated extensions that remained connected to the GUV, yielding a ‘star-fish' like appearance. Some extensions were more than 10 µm long. Notably, the persistence length was much greater than the length of the tubules. Fluorescence intensity was fairly uniform, indicating that all tubular extensions had a uniform, defined thickness.