2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/4130We present near-infrared photometry of a large sample of planetary nebulae (PNe) and show that the IJK colours are a good tool to distinguish different classes of PNe, like nebulae around symbiotic Miras or IR-[WC] PNe from genuine PNe.2 pages, 1 figure; Proceedings of IAU Symposium 209 "Planetary Nebulae: Their Evolution and Role in the Universe", in pressAstrophysicstext