The hitboxes for anchors are the whole sprite of an object. This gets really annoing for certain builds.
In the following image you can see an anchor in mid air which connects the plank with the balloon, in the second image you can see a representation of the anchor hitboxes:

You can summon arrow anchors at the point where the hitboxes overlap.
Note: The usage of restorative does not change the anchor hitbox, I only used it so it's easier to demonstrate the mid air anchor.

This does not only count for arrow anchors but also for normal anchors on objects, as shown in the next example:
In the first picture you can see a stable v-only build with normal planks, the solid plank only connects its anchor to the vertical plank. It collides with the angled ghost plank. In the second picture the solid plank connected its anchor to both the vertical plank and also to the angled ghost plank. This causes the solid plank to phase through this angled plank, making the build instable.


I guess it would be best to keep the anchoring zone in the physical hitbox of the object.

My personal frustration with this is the fact that I cannot put together a decent looking set of customized shaman objects which doesn't interfere with the game mechanics. Being able to customize the normal wooden planks' colour would be great, too, as all I want are white planks.

i thought this was intended, like it's hard to attach a balloon on a mouse sat on a cloud cos the hitbox for the coud is so huge and square compared to the shape of the sprite. you bring up good points about shaman customs interfering with mechanics tho, maybe they'll do something about it now

fix this, tig

Well it may cause some issues with how people use anvils, I'd say limit it to the non transparent areas of an object to be safer (since balloons have always been smaller than their sprite size)

I also think that removing the anchor hitzone in the transparent areas would be the best solution. Either way, I highly doubt that this issue will be solved at all, as most people don't even care about how they build or how to build properly. I rather made this thread just to have it on record.

I'm pretty sure this will become more apparent the fancier shaman item skins become ._. It's already relatively hindering in the example of the baloon you posted