How can I make just one particular part shiny?

So I’ve made a mattress, and it’s supposed to have a blood stain on it. How can I make just the blood part have roughness and metallic on? So it reflects like fresh blood. I’ve tried a spec map but it’s not how I want it.

Help please? Thanks :slight_smile:

http://s28.postimg.org/zdbs1agf1/mattress.png

http://s26.postimg.org/4g57g1f15/Bed_2048_Stained_Blood_Bright1.jpg

http://s26.postimg.org/pebde4evr/Bed_2048_Stained_Blood_Bright_Spec.jpg

The Diffuse has my name branding on because is for a University Project and if lecturers decide to research into my assets and they see it on a forum, they can count that as plagiarism, even though I have the oiginals lol.

You can use a alpha texture. The metallic and roughness can be affected with a texture just like a specular map does. You could also use Layered Materials. We have a Layered Materials Tutorial as well. I hope helps!

I personally multiply the roughness and metallic by a mask (RGB or BW)