I'm using Blender 4.2.1. I created the section of the head to attach the eyelashes and called it eyelash base. I shrinkwrapped it to the head and am trying to make it invisible. I gave it a material with a Transparent BSDF with Alpha of 0 and turned off Transparent Shadows under material properties. This works with eevee but no matter what I try Cycles shows the eyelash base as a very visible gray-brown color, even when I hide and disable it in viewport and render. Any advice? Since I'm a noob I assume this is my error rather than a software bug.
With the object selected goto properties editor object tab visibility panel and uncheck shadow.
You can also just click camera icon in outliner to disable in rendering. This works for both engines.
There could be a couple things going on. Can you attach some screenshots?
Maybe you have an extra mesh there that you have to disable in the viewport as well? Perhaps you have the transparency bounces at 0?
If you're using a particle system, you have to go to viewport display and uncheck show emitter I think. It could be many other things, but screenshots will help.