Save your customised cover image in your Photo Album then upload it in Noteshelf in two ways:
1. For new notebooks, from the + icon on the Main Shelf, tap on "Pen icon" on the Cover/Paper then swipe all the way to the bottom of this selection screen to find the "Custom" option. Here, you just need to tap on 'Plus' icon to to upload your desired cover image from your Photo Album.
2. For existing notebooks, tap and hold on one or tap on the Edit icon from the Main Shelf then tap on the Edit icon on desired notebook. From there, it is the same procedure as above.
Recommended Dimensions are:
For a custom cover, the best dimensions are 3520 x 1880 px.
For a paper, they are 1472 x 1848 px including a non-writable 120 px footer.
For best results, use an image with transparent or white background.
In order to edit this custom cover/paper's title color and position later, you just need to do a long tap on the custom cover/paper and tap on the pen icon.
1. Tap on Plus icon on shelf then select covers and swipe all the way to the both to find custom covers/papers
2. Long tap on the cover/paper you want to delete
3. Hit the cross icon to delete/pen icon to edit cover/paper