Here's an example of what I mean:
![Image](https://i.postimg.cc/HnF76Y8W/essers-stretched.jpg)
The top is normal size, the second line the height is the same but the length is stretched and the third the height is the same but the length is shortened. I used H.Essers logo because you used it on one of your skins, and I bring this up because the Earth is misshapen in a couple of places on your truck, indicating the length of the image has been shortened to make it fit where you wanted it to go.
Also, my Father used to tell me (about rock guitar sound) "You can take a clean sound and distort it, but you can't take a distorted sound and clean it up." The same idea applies to image size. So think in terms of you can take a large image and make it small, but you can't take a small image and make it large. Down sizing an image usually looks ok, if you do it right. But to make a small image larger almost never works. The reason for this is when you make a large image smaller, you are taking pixels out of the image. And if you do it right, it should turn out ok. Specially if the large image is very high quality. But to make a small image larger, you have to add pixels that were not there to begin with and most software does a horrible job of that.
I hope this helps you in your learning process.
Ax
Keep On Truckin'...