As previously stated how thick you apply the medium determines how definitive the cracks are. And you can not streak the paint color over more than once. I use a wide brush loaded heavy and make one swipe till the paint runs out, reload and do it again. If you recoat the paint it will not crack through more than one layer of paint. You can do it again if you put the medium down and start over. The drying time of the medium can make a difference as well; each brand usually has it's own recommendation. I usually let it sit a couple hours. Good luck

Hey Russ - yes, I like not only the outcome of the turface, but the simplicity! I can order a 50 pound bag and it will be enough for a couple years I think. I do filter using a mesh strainer - I know some folks get really technical and use bonsai sifters, but I haven't felt the need thus far. I separate coarse material for relatively mature plants and the fines are used for cuttings. Some cuttings, I use unsifted turface, such as jades: I figured they need the fines to start rooting, but need more drainage than the average cutting. I haven't lost a single jade cutting using this approach. I have some azalea cuttings, euonymous, and bougainvillea that are all doing well in turface fines, simply sitting on my front porch (no extra cover for humidity, getting dappled morning sun). My Fernwood (or japonica) sans put out a lot of new growth including a flower when I switched to turface from Gritty Mix, but I haven't tried my trifasciata or cylindrical in turface yet. Al (Tapla) talks about gritty mix on other threads; I'm going to try to paraphrase, and hope I don't misinterpret anything. Bark is the organic that holds a lot of water, but is slow to abosrb, which is why we often soak bark before using it: otherwise all the water runs right over it and out the bottom. I believe one of his stated reasons for granite, beyond drainage without holding water for longer periods, is that it does hold drops of water on it's exterior after watering which can be absorbed more slowly by bark. AKA, it helps bark absorb/retain water. However, when I've repotted plants in gritty mix, I've found the top to be dry and sometimes more moisture (not humidity) in the lower parts of the pot, presumably because of water sitting on granite. Conversely with turface, it gets absorbed quickly, it doesn't sit in drops or pools, and it gets released slowly/consistently as humidity, which is what roots want: a combination of H20 and O2. That being said, Al is many fold more knowledgeable than me - these are just my musings as I spend way too much time watching my plants ;) Regarding "improve other aspects of care," I think your right, people have more access to ideas and information, this thread being a great example. I look back on the way I approached my plants a few years ago while I was just starting to absorb information from this site and other sources, and I've made great improvements (with a long way to go still). So while I learned here that no amount of perlite will fix miracle grow (at some point, the plants simply fall out of the pot because the perlite is so light!), I also learned a lot of other things, so it is hard to compare the results I had with soil to the results I'm getting with turface.

Also the wood needs to be either a) kiln dried or b) air stacked and allowed to dry in a dry room with limited humidity for about a year or it will shrink and attempt to curl awfully bad as it dries in place after being nailed up...............

Assuming it is open to the ground on the bottom, any bagged raised bed soil will work. Ideally, you want well draining, mineral based garden soil (aka "dirt") with a small amount of compost or other organic matter added. I hope it is a very small tree. Or one trained as an espalier.