Question Regarding Determining The Condition Of A Stamp For Possible Use In Trading.

I am a relative beginner and would appreciate advice on determining whether or not a stamp would be suitable to use for trading. I do not intend to post any stamps for trading on this site at present. I only wish to gain a better understanding of how to make a proper determination of a stamp's condition to know whether a stamp that I am not interested in should be saved for a possible future trade or thrown away.

Here is a sample stamp.



This stamp has a few perforations torn off in the upper left corner. Would it be acceptable for use in trading or should I just throw it away?




I realize this question is somewhat subjective, but any advice would be appreciated.

Thanks

Hi, there's also what looks like a brown stain midway along the top of the stamp, and pen marks in the bottom margin. I guess that's a throwaway!

You can simply ask yourself : would I be happy when I receive this stamp?

When the answer is no then you throw this type of stamps away.