It never hurts to overwrite more information than necessary when you're concerned about secrecy. One possible thing to be wary of is JPEG compression artifacts around the secret data, which could be used to get clues about the shape of the text. Of course, Paint doesn't have any special effects, so you should be fine. Some effects can be undone almost perfectly, so make sure the one you use involves a lot of randomness or actual data destruction (e.g. If you use a blur rather than a plain opaque rectangle/brush, a determined attacker could try lots of different possibilities in the image to see what text(s) get close to your image when blurred.

Any spaces in the blanked region provide information about the relative lengths of the data's parts/words (mentioned in David Schwartz's comment).

The height of the region could tell attackers whether the text representation of the data has ascenders or descenders (like in the letters b and p).

The width of the blanked region places an upper bound on the length of the secret data.

(Paint doesn't.) There are some things to watch out for, though: Personally, I am happy to see the classic Paint app bundled with Windows 10.As mentioned in the answers to a very similar question, scribbling over part of an image will destroy the original pixels, assuming that your editor doesn't store any layers or undo history in the saved image. It looks like Microsoft has eventually figured out using the collected Telemetry data that only a small number of users actually use Paint 3D instead of the classic Paint app. It'll remain included in Windows 10 for now. Starting in Windows 10 Insider Preview build 18334 Microsoft has silently removed the Product Alert notice. Classic Paint always loaded much faster, and had a more usable and friendlier user interface with superior mouse and keyboard usability.

They were not ready to exchange the good old mspaint.exe with a completely different Store app because the old Paint has its own advantages and Paint 3D does not surpass it in every way. Many people were not happy with this move from Microsoft. The app has tools to transform 2D drawings into 3D objects. It comes with tools like markers, brushes, various art tools to help users create objects. Paint 3D is the new Universal Windows Platform app and its user interface is completely different from Classic Paint.

Does ms paint support layers