I too would be surprised if oil-base were problematic. Latex is a relatively new product, and it seems like the practice of painting trunks goes back well before its common availability. Old timers may have been using milk paint but I suspect white lead was what was getting put down. In terms of breathing...many studies have shown that over finished goods it takes 3 plus coats of any paint (with the exception of epoxies and shellac) to develop an appreciable barrier to vapor and oxygen transfer. This might not directly transcribe to living tissue but would seem to hint that a single coat of either won't get you in much trouble in that regard. Do we even know how much "breathing" is occuring in this area? Brandon, I too would be interested in the paper you mentioned. Often cell damage from freezing is not so much bursting...although this certainly happens, but micro punctures to cell walls and internal structures. This gets caused by tiny needle-like ice crystals that form in a "slushy" environment where solid freeze can't. Such damage might explain the more gradual failure Harvestman notes as opposed to rapid and complete collapse that total cell rupture usually causes in herbaceous plants?

If you cut the ivy stems at the base of the tree, the cut stems are all that you need to apply a herbicide to - the severed top growth will die naturally. And rather than glyphosate (RoundUp), I'd suggest you treat the cut stems with something a bit stronger, like triclopyr (Bayer's Brush Killer). Once the top growth dies, you can pull it off the tree gently.......the rootlets should begin to release on their own. This is a very common practice in my region, where English ivy is a majorly aggressive invasive species and inhabits all manner of trees in tended and untended areas. Because ivy is evergreen and quite dense when established, it has an ability to trap and retain moisture against the tree bark - that can cause the bark to rot and fall of in places and can make portions of the tree a bit soft and mushy. Trees can lose large chunks of bark generally without issue. You just want to avoid stripping it off completely around the trunk circumference. Getting the ivy removed and letting things dry out properly is likely all you need to do!

They can but it is not easy. It requires much more attention and hands-on work than does grafting so more expensive and not yet commercially viable. Apparently the EU is much better at this than we are on this side of the pond, as both Germany and the Netherlands have begun to heavily market cutting grown Japanese maples. Not sure about what other varieties they have been exploring this technique with but we have had some discussions about this on the Maples forum as our European members are purchasing and growing these cutting grown trees. As to the OP's paperbark, I'd get a certified arborist/horticulturist out who is experienced in tree pathology to look at this issue. Whatever is growing on these trunks doesn't look good and if it is the Irpex lacteus as I suspect (maples are a primary host), then some serious attention is needed ASAP!! I also agree with Toronado that large paperbarks are not common - this is just not a big growing tree. A 60+ year old one nearby is perhaps 20' tall and maybe 25' wide. Larger ones are known but are not common - perhaps the largest is located in Bodnant Gardens, Wales.

The two different photos are showing two different problems. The first is clearly leafminer damage, which is seldom ever a cause for concern. It is difficult to treat as the insect causing the problem is protected by the exterior plant tissue (it lives and feeds inside the foliage). But as stated previously, while it may account for some minor leaf loss and disfigurement, it is primarily a cosmetic issue. The second photo does look like there may be some sort of fungal issue. Neem oil is a decent fungicide but like most fungicides, it is only prophylactic so will not "cure" existing problems, only limit or curtail their spread. ETA: the tree looks very skinny and congested with regards to the foliage. That might be creating issues with proper air circulation, which can be a big contributor to fungal problems. Having never gown this tree myself, I am not familiar with its growing habit or pruning requirements, but some spacers placed between the three major stalks/trunks may be appropriate and helpful.