I have been using Mission Model paint and really like it. With my last order I got a couple of bottles of MMW-004, which is Transparent Medium. I have no idea on how to use this paint. Any help appreciated.

it is practically the carrier without the pigment, the resin that makes up the paint itself without the color, added to a color make it more transparent without losing the consistency, thinn the color without thinner, you can use it to give light layers of dust, post -shading, light layers of rust or filters, usually do more or less the same thing by adding thinner but over a certain amount the thinner ruins the paint because it reaches the point that the carrier is too diluted and the pigment settles or not grip anymore 'well to the surface and becomes a wash, even the shelf-life is shortened, instead so' the gripping power and the shelf-life is the same as a new bottle of paint, in theory adding pigment you could make your own colors ...in theory... I do not know if there's another brand of modeling paint that sells its carrier like that

I love me to MMP,the only think i dont use is there primer but only becose i already have the Badger one.

Vallejo sells Gloss and Matte Medium that I guess should be similar to this:
http://www.acrylicosvallejo.com/en_US/model-paints/auxiliary-products/3

Same for Ammo and their Transparator:
https://www.migjimenez.com/en/acrylic-colors/615-transparator-60-ml.html

Thanks Carlos...i forgot the Trasparator from Ammo,from Vallejo probably the best mach is the Glaze Medium,no Matt or Gloss agent only the carrier

Thanks gentlemen. I'll try it on some old model and see what happens.