Quote from: Bestcoin-fan on August 16, 2018, 08:57:50 AM

Look, on my online Desktop PC I want to send bitcoins to somewhere. They usually provide me with a QR Code which I would have just scanned with my Android watch-only wallet, export (save) the transaction file, and then signed it on my offline cold Storage notebook, then I'd again export it back to my Android (or PC's ) watch-only wallet for broadcasting.
That would be quick and fine!

Well, you can skip the mobile phone and it will be even faster.

1) Create unsigned transaction on your online PC and display the QR
2) Scan the QR code with your offline computer
3) Sign the transaction and display the QR
4) Scan the QR code with your online computer
5) Broadcast the transaction

But you could also (if you don't have webcams or don't want to use them) do this:

1) Create unsigned tx on your online PC and display the QR
2) Make a photo of the QR code with your mobile phone
3) Move the photo onto your offline PC
4) Use a QR code reader software on your offline PC to decode the data
5) Import the unsigned TX into electrum
6) Sign the transaction and display the QR
7) Do 2) - 5) with the signed tx from your offline pc -> online pc
8] Broadcast the TX

The second approach is more time consuming and requires a software to extract data from QR codes installed on your online AND offline PC.
I, personally, would choose the first option for dedicated offline storage.