How to force copy and paste from clipboard to Mail.app to use PNG?

[laz232]

Most of the time I take a screenshot, edit, then copy and paste to Mail.app (I don't save the intermediate, because it's ephemeral)
But the pasted graphic, unbeknownst to me - becomes a TIFF - which has %#$ support in the rest of the world.
I realised this when after a year or two many clients told me they did not realise I was sending them marked-up drawings!

This is for work email - how do I force macOS to paste PNGs from clipboard?

macOS 10.15.7

 

[Slartibart]

You choose a size less than "larger" in the Mail "Image Size" selector, it changes TIFF's to JPEG. After that your pasted pic is called pastedGraphic.jpg. If you want preserve the original dimensions you have to add your JPEG as an attachment to Mail.

Otherwise the image format of the clipboard is TIFF (and has been for the last 2 decades on Macs). How it is handled depends on the program your copying from.

EDIT: You can actually put a JPEG image in the clipboard using Applescript like this at the command-line:

osascript -e 'set the clipboard to (read (POSIX file "/Users/YourUserName/Desktop/a.jpg") as JPEG picture)'

EDIT II: actually somebody wrote a little tool for that.

 

[BrianBaughn]

If you don't mind all of your screenshots being PNG to start with you can change the default for screenshots.

Just use PNG instead of JPG.