[en] Compete text of publication follows. The capillary guiding phenomena is a result of a self-organizing process governing the charge deposition by the incident ions at the inner wall of the capillaries. The ions are deflected by charge patches so they do not suffer close collisions with the capillary wall, even when the capillary axis is tilted with respect to the incident beam direction. This 'fully elastic' guiding has been found to be significant in capillaries of different sizes and aspect ratios, made from different insulator materials, in a wide range of impact ion energies and charge states. In this work, guiding 3-keV Ne⁷⁺ ions through nanocapillaries in insulating polyethylene terephthalate was investigated as function of the capillary diameter. The experiments were conducted at the ZERNIKE-LEIF facility at the KVI Groningen (Netherlands). Highly parallel capillaries with a density of 4 x 10⁶ cm² and diameters of 100, 150, 200, 300, and 400 nm were utilized. The characteristic charges governing the charge evolution of the total ion yield were found to be independent of the capillary diameter. However, certain dynamic properties were found to change significantly with this diameter: The transmission profiles of the 100 nm capillaries are broad and structureless, whereas those for 300 nm are composed of three peaks and the mean angle oscillates with deposited charge. At equilibrium the total ion yield was studied as a function of the tilt angle. The results were used to evaluate guiding angles (see Fig. 1 (b)), which were found to be almost constant near 5.5 deg with varying capillary diameter similarly as the characteristic charge governing the charge evolution. Model considerations were applied to interpret the results. They have led to the conclusions that the effective potential and the capacity of the capillary samples are nearly independent on the diameter. These unexpected results imply the need for further investigations. Acknowledgements. B.S. and Z.J. were supported by the Hungarian National Science Foundation OTKA (No. K73703 and No. PD050000). The work was financially supported by the European Network ITS-LEIF RII3- 026015.