Arnold Textures with Alpha Limits

[mphillips0007]

Not sure what I am doing wrong.  I am working on a project which includes a mother board.  I have made labels for all the circuits in photoshop and save them with alpha.  I need approximately 20 labels. I set the texture to - flat projection - disable Tile and Seamless - scale the texture accordingly and under Alpha stacking I chose Mode - Shader - Shader image(image) and select Use alpha channel.  This works great until I have about 9 textures then when I add new materials it will make other materials disappear.  I am assuming it reads the textures Left - Right.  Is this the wrong workflow for adding labels to objects or is there a limit on number of textures per object?

[peter_horvath]

Stacking uses a layer shader under the hood, which supports 8 inputs, so indeed, currently it's limited to 8 materials.

You can instead setup your layers inside your material and chain multiple layer shaders to handle more inputs, something like this: