Posted:
Well, I can suggest various ways, but it depends how much security you want. The more hard you wanna make it for others to pass this as their own work, the more work it will take.
First of all, a screenshot can be taken of anything. If you can view it, you can take a screenshot. Therefore it doesn't matter which format you use for text, someone can simply take a screenshot and post it elsewhere. But they won't be editable easily. If someone is gonna put an effort, they can still convert image to text by OCR and edit it but most won't want to put that much work.
The best route I will suggest is to use repeating watermarks. It is a method of filling whole of your text with watermarks. You can make it nearly transparent and it will become very subtle. If someone posts it then, it will contain the author's name and/or IF name as you wish.
The way you could achieve this is to type it in word. Then use a software that will automatically turn the document into images. Now, you have two ways. Either you can apply watermark individually to each images but it will be very time consuming. So, the better path is to first create an image with the repeated watermark pattern. And then you could add the image as picture watermark in Word. And then when you will convert the document into images, it will be with repeated watermark all over the text.
An example of what I am talking about.
Of course this is just and example and you may change the orientation, color, transparency according to your wishes.
Hope this helps.
Arjun
