What is the correct way to do a spot varnish?

[itsallgoode9]

II render lots of product labels with areas of spot varnish on them (think high gloss text on matte paper stock) and wondering what the correct to achieve this effect is. I was working with it tonight and was just using a black and white image in the roughness slot, but is a pretty inefficent workflow since there's no easy way that I can see to adjust the separate roughness value in the program. Consider that if you needed different levels of glossiness (high gloss, semi gloss and matte in the same material) that it's a pain in the ass to not be able to see the results of your roughness, in realtime, in the program.

Is that the correct/only way to achieve this effect in octane render currently?

here's a very simple image sample of what i'm talking about.

[lixai]

here is a example scene, hope this helps

text example.zip

(208.74 KiB) Downloaded 161 times

the scene is for max 2013 and above

[itsallgoode9]

Thanks for putting that sample scene together but I unfortunately do have not have Max, I'm a maya guy. do you mind giving me a quick overview of how you setup your material? Did you set it up in the same way I described in my initial post, or is that the wrong way to go about it? Thanks!

[lixai]

easy,
just use the texture file from my previous post and put it in the roughness slot (glossy material), make the diffuse slot a dark color.
i also used the same texture (inverted) to add bump.
let me know if you need any further help.

[gordonrobb]

An easy way is to have the glossy material you want for the 'spot varnish' and the plain material you want for the rest, and to use a material mix node that just uses a black and white image of the text to mix the two. That way, you can then adjust each material independently.

[glimpse]

Make a mix material (from two materrials: matte & gloss)
with the help of the mask =) then You can adjust every material as You wish

to get more believable effect of paint (silkscreened on a surface) add a bump/normal map with slight imperfections =)

[itsallgoode9]

thanks guys. The mix material is more what i'm after.

Using the mix material, can I overlay a material of clear varnish (masked if needed) on top of the base material? basically a material that is clear, with no texture, in the same way that a varnish would work in real life (example: matte paper as a base, with a clear layer of varnish applied on top of the paper)? If so, how would I go about doing that? That would keep things a lot cleaner in terms of material creation to do it like that instead of duplicating the entire material, with all its textures, just to create a gloss effect on a couple lines of text.

also, it looks like i'm stuck with only 2 materials being able to be combined as far as I can tell? That's a bit of a hurdle for me, I have to say. sometimes I might have 2 or 3 different colored foils of different roughness or color on a label along with 2 or 3 different levels of varnish roughness. In Maxwell Render I could layer as I needed, which made these complicated label materials much easier to do.

[lixai]

you can mix 2 materials, and mix another material with the mixed material.
not as easy as maxwell but working

[itsallgoode9]

you can mix 2 materials, and mix another material with the mixed material.
not as easy as maxwell but working

hmm, maybe it doesn't work in the maya plugin? i tried it but it just gives me an error.

Actually, now all of a sudden my mix material in maya plugin is completely broken. i can't even put a diffuse material into a mix material without getting an error....that's not good. worked fine a couple hrs ago. argh

[glimpse]

ghm,..don't know about maya, but it works perfectly in StandAlone:

two masks (one between glossy/matte blacks & other between black/white)
pluss a normal for some bumpy-ness (might be a bit too much =)

& that bump does a bit of a difference if You're looking to get desired effect, without it material isn't nearly as convincing, as You loose these reflections on the edges of pait -
here's the fast comparison without ripples =)