Here is a tip on how to maintain font text properties after copy and paste in iOS mail signature.
Sometimes you may want to copy and paste text that may contain rich properties like image, font color, size of text, special character and so on. It usually ends in frustration for Apple users because when you copy into iOS the font and color usually default to iOS settings.
iOS mail signature default settings would send text in plain text.
Here is the trick to do;
After copy and paste action, just shake the Apple iPhone and the text will revert to the original state.
(Note this procedure may change with updates to iOS)
In iOS 9 and lesser it was a different technique;
Press to the right-hand side of the image, and then type a few spaces on the keyboard. This will create white space.
Hold down your finger over the white space to select it. Once it is selected, click the ‘B I U‘ button. (# is just there to show where the white space will be.)
Now press the ‘Bold’ button.
Once the white space has been made ‘Bold’ simply click ”Mail…’ at the top left of the screen.