Hello!
I’m a new user of this fantastic tool, but I’ve a big problem:
when I import the map in Unity, the prefab is in very low resolution.
I’m exercising in 2d top down game, trying to creating my first map with Tiled…all ok, all perfect, I followed a lot of guides about this.
Then I used Tiled2Unity: even here all perfect, all done, the preview is glorious!
And then…well, I go in Unity, pick my prefab and…very low resolution.
I tried to change a lot of settings, re-import this, even the png of the tileset, but I have no idea how can I do…I searched a lot on Google, a lot on this forum, but nothing…sigh…
Sorry, I’m a newbie :c
Edit: I found the solution! In the exported folder in Unity, I went in the textures folder, selected the image and changed the Max Size value to 8192!
Now the prefab looks perfect! 
