A few weeks ago I picked up a Weathering Stick by Tamiya. A couple of people were interested in how good this product was but at the time it was new to me too. I've now had a chance to use this product... and I like it. The Tamiya Weathering Stick is a pen-type tool advertised as "achieving realistic finishing effects on scale models". I bought the Mud pen for use on my growing WWII Panzer Company but at £4.95 it wasn't cheep. Now that I have used it I consider this a good investment.
The Pen has a twist delivery system whereby the Mud stick is propelled from (or pulled back into) the dispenser. The Lid provides an air tight seal preventing the Mud from drying up. The Mud itself is sticky and clumpy but quite soft and is easy to apply. My only gripe with the dispenser is that the Mud comes in a flat head approximately 5mm in diameter. Personally I found this a rather 'blunt instrument' compared to using a brush. Indeed the Tamiya site itself suggests using a small brush to transfer the Mud from the pen to small details for more precise application.
My first impression of the Weathering stick is that it produces a similar look to dry brushed weathering but unlike dry brushing the Tamiya pen leaves behind three dimensional mud. For example I used the pen to put mud on the tracks of my latest Tank Platoon and the tracks got filled up with 'clods' of earth while the sides of the tanks were streaked with 'splashed' mud. I then used a toothpick to pluck out the excess. At this stage the material is still soft and pliable but dries hard on exposure to air. I haven't varnished over the Mud yet but I doubt if this will give any problems.
I think these pens were designed for application on larger models (1/35 and above) but I think the effect looks pretty good even on 15mm 1/100th scale models. The Mud colour I used (and shown above) isn't overwhelming and certainly suits the models and the battle theatre I am using it for. Having used this accessory I will definitely be buying some of the other Weathering Pens in the Tamiya range.