Yesterday, 03:59 PM
You got the solution in post #2 - beware of active selections.
More generally each time you adjust an image or layer, there will be some degradation, not really applicable in this case, just a comment. You can mitigate to a certain extent by using the Unified Transform Tool (scale - rotate - shear..all-in-one) but it does take practise.
When it comes to Save / Export the Gimp Save (a .xcf) is lossless and keeps layers / guides / selections...
What you can do at the end of editing is Layer -> New from Visible and that sometimes helps visualising the final mage
For export a jpeg is a lossy format ang png is lossless. Depends on requirements.
Another quick animation: https://i.imgur.com/6J8C5jS.mp4
More generally each time you adjust an image or layer, there will be some degradation, not really applicable in this case, just a comment. You can mitigate to a certain extent by using the Unified Transform Tool (scale - rotate - shear..all-in-one) but it does take practise.
When it comes to Save / Export the Gimp Save (a .xcf) is lossless and keeps layers / guides / selections...
What you can do at the end of editing is Layer -> New from Visible and that sometimes helps visualising the final mage
For export a jpeg is a lossy format ang png is lossless. Depends on requirements.
Another quick animation: https://i.imgur.com/6J8C5jS.mp4