A wideband dual-reflector 3D-printed antenna is proposed to operate in the mm-Wave band. The design is based on a Cassegrain reflector optics but including a dielectric piece for merging the feeding system and the support structure of the subreflector. The operational principle of this antenna is presented, as well as the design parameters. Then, a prototype to operate at Ka-band is manufactured combining a 3D-printed technique using PLA as printable material and a spray to coating the antenna, providing a low-cost affordable solution. The different pieces of the antenna are evaluated, and the antenna is also measured in a spherical compact range. An excellent agreement between simulations and measurements is obtained, resulting in a\documentclass[12pt]{minimal}
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				\begin{document}$$48.2\%$$\end{document}48.2%of operational bandwidth. These results validate the use of coating procedures and the design technique at these demanding frequencies. Its operation shows a stable gain in the entire Ka-band (including\documentclass[12pt]{minimal}
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				\begin{document}$$28$$\end{document}28and\documentclass[12pt]{minimal}
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				\begin{document}$$39 \mathrm{GHz}$$\end{document}39GHz), which makes the antenna as a suitable light, low-cost, and broadband solution for mm-Wave applications.