Best Medium for thining GW Washes

[sbarnby71]

I'm looking to thin a GW Wash Drakenhof Nightshade by about 50% and I know that at that level water will not give a great result.  Can anyone recommend a good thinner.  I currently have:

GW Lahmian Medium

Vallejo Airbrush Flow Improver

Vallejo Matt Medium

Vallejo Thinner Medium

Liquitex Airbrush Medium

 

[Arkhanist]

Tale of painters did a test of various mediums for diluting washes, contrast and normal paint, but didn't include artist grade ones alas.

The main one to avoid is lahmian medium; it's ok in small doses for base paints etc, but not for heavy thinning. The best one, particularly for washes was GW contrast medium. I can concur with this one from personal experience, it basically makes GW shades into super-washes that seek out the crevices really well, and gives smooth transitions - see the agrax earthshade example, and is my go-to for thinning washes to stain less while still making them work like washes.

I've not used vallejo (brush) thinner, but the airbrush version works well for reducing thick paint down.

A little flow aid is useful for breaking surface tension and make paint well, flow better off the brush and into crevices - handy for paints that dry chalky, or in the airbrush when it's a bit cloggy - but I've found it does weird things to the paint if you push it too far.

I have used liquitex airbrush medium for thinning brush paints and that works well, and can push paint further than vallejo airbrush thinner due to a higher medium content (works better for brush than it does for airbrushing, IMO!), and for washes if you want to make them more glaze-like to e.g. do ghost effects. So I'd say it depends what you're looking to do with thinning the wash - keep the wash recess-seeking properties but less intense colour, or thin it to more glaze-like thin paint so you can do more even staining of the surface?

If it's the first, then getting some GW Contrast medium is basically the best choice.

If it's more glaze-like you're after, liquitex airbrush medium will do that without causing paint breakdown as water will. Assuming the consistency of the vallejo thinner medium is liquid enough, it should also work similarly. Liquitex airbrush medium is quite milky white in appearance, so adjusts the colour when first used, but that disappears when it dries.

Another product I've been trying out lately is instar "water plus" which definitely also works nicely as a thinner, and has become my standard go-to for thinning base/layer paints for now, but it's only a relatively small improvement over liquitex airbrush medium, which you already have.

Glaze medium is another option for turning it into a glaze, but I've always found they bump the drying time waaaay too high into annoying territory.

Edited June 27, 2022 by Arkhanist

[sbarnby71]

Thanks for the great info!  I'm really impressed by the results with the Agrax Earthshade, that's the effect I'm after, but with Blue.  Now for a bit of background of what I'm trying to do.

Baby Blue Space Wolves (yep not to everyone's taste, but that how I like them), I want my main colour to be Fenrisian Grey, to achieve this I airbrush using Vallejo Mecha Primer Grey as a base, then several coats of Air Fenrisian Grey until I get a good solid light baby blue.  I used to hand paint each joint and crevice in the armour using the old GW Space Wolves Grey and it takes weeks of touching up and re-doing.  So I wanted a lazy way to recess with a darkish blue but not have to go back and do so much touch up on the light Fenrisian Grey as because it is a Layer or Air paint, it takes several coats to correct a darker blue mistake and never gives as smooth a finish. 

My most recent process would be to use a thinned Contrast Space Wolves Grey about 50/50 with Contrast Medium on top of a gloss varnish to protect the baby-blue, but it still causes staining on the flat armour plates.  So after speaking to the guy in my local hobby store he said I should be using a Wash, not a Contrast paint if I want to minimize the staining.

Based on the picture, the way to go would be Drakenhof Nightshade thinned 2:3 with Contrast Medium.

[Arkhanist]

Yes, I think that's a solid plan, I use a very similar approach for a number of my washes these days, and should definitely need a lot less cleanup than space wolves grey. You can play around with the contrast ratio somewhat, it's quite flexible.

Another option is the same idea, but change the order! For darker washes, you can still get a little surface staining (check around the top of the backpack for the agrax example above) or pooling if you miss it around the feet etc.

So what you can do is steal an idea from the scale model community, and do a pre-shade. Basically you do the contrast+shade wash over the primer - in this case, after the mecha grey primer - to get the crevice shading. Any mild staining on the plates you can easily fix by brushing on primer over it which usually covers in a single layer. Then you do the main coat, fenrisian grey by airbrush, but the recess shading should still show through the thin airbrush layers.

It depends how heavy the fenrisian grey goes on, because it will mute the recess shading somewhat (so you may need to do the wash darker) - but also means you don't need to do any cleanup at all after the airbrush base coat! So perhaps try both ways and see which works better for you.

Also bear in mind that the shades are being redone soon (in 18ml pots), and they look like they will have some of that same effect out the bottle, though not as much as mixing in contrast.

[sbarnby71]

I was wondering if the new formula of the Washes would help me out here.  I have tried un-thinned Drakenhof wash many years ago and it was just too dark so I dismissed it at the time (I didn't look into thinning it).  I'll give the thinned Drakenhof a try as I have the pot from years ago and don't use it for anything else.

I also like the idea of the pre-shade.  Only downside for me is I have 30+ already based and in progress pieces, but I can do a test run and see if it will be easier for future projects, it will also most likely allow me to use un-thinned Drakenhof as the Air Space Wolves Grey will mute it.

 

[sbarnby71]

Did some quick tests over my lunch-hour with a 1 part Shade to 3 parts Contrast Medium - I figure I can always do a second coat if I want to go darker or just use some un-thinned Shade in the real deep recesses.  Fairly happy with the results on armoured hands the shade is subtle as I wanted it to be.

What did strike me was how the colours look when I'd put them in Dropper Bottles.  On the left is my 1:3 Shade/Contrast Medium, on the right is pure Space Wolves Grey Contrast paint.  They were both shaken at the same time and after 5 mins you can see the Shade has almost left the bottle clean, whereas the pure Contrast has stained the bottle completely.  I didn't take a picture of the Drakenhof in it's pot, but it leaves very heavy staining on the pot.  So I am very hopeful for the thinned shade not leaving too much staining on the flat surfaces.