Error Questions From A Newbie.

So I am pretty new to collecting and I have a couple questions about errors. How much misalignment does there need to be on a stamp for it to be considered an error? (See the Lindberg stamp below) Similarly, how much color variation does there need to be for it to be considered an error? (See the 15 cent special delivery stamps below) How much (if at all) does this affect their value? Thanks in advance.

Hi Rhoulaki, and welcome to the forum! None of the examples that you are showing are errors. In the case of the airmail stamp, it is just poorly centered. That and the lack of perforation on the right side may make it less desirable!
The color change of the special delivery stamp would be of interest to a specialty collector; one who collects all possible shades of a stamps' color. Again, this would not be an error. Only if a totally different color ink was used can one speak of an error!

Peter

Also note the orange color as is the 15-cent Special Delivery stamps can sometimes be described as a "color changeling". In other words, the stamps were exposed to too much light and/or some sort of chemical exposure that was applied when the stamps were soaked off paper. In both cases, these are considered damaged stamps and likely worth less than a normal example. Many orange colored stamps from the early 20th century are easily prone to color abnormalities such as this.

The bottom Special Delivery is oxidized. Put it in some 3% hydrogen peroxide for a couple of minutes and the orange color will return. Both 19th and 20th century orange stamps have this occur regularly. It's almost as common as breathing on 1862-1875 revenues.

They have definitely never been used and I'm pretty sure they have been kept wrapped under plastic since they were new (the card they are laying on is at least 50 years old). Does that mean that they are OK, or are they still considered less valuable?

Lets see what else you got.

And welcome to the hobby!

Wrapping in plastic doesn't prevent oxidation, nor does it improve the centering. They are somewhat inferior copies, but not without value; not everyone can afford AAA+ stamps.

You will lose any remaining gum on the stamp if you put it in hydrogen peroxide solution, as the solution is water-based.

Just a minor clarification...

A common misconception is that the blackened layer is being converted back to the original orange ink. That is not what is happening.

This particular color change is caused by sulfur pollutants in the air reacting with stamp ink. That original surface layer of ink can not be restored to its original color using hydrogen peroxide. By soaking in hydrogen peroxide, you are chemically altering the blackened ink layer into a semi-transparent layer, so that you can see the underlying ink. You are neither removing the sulfur, nor are you changing the ink back to its original color. You are merely converting the blackened layer of ink into something "invisible" to the naked eye.

There are many collectors who consider this chemical alteration as acceptable. However, do understand that it is a chemical alteration of the stamp.

Enjoy your stamps!

The stamp does not have to be immersed in hydrogen peroxide, holding the stamp over the liquid in the fumes will work.

Yes, when done properly, that is one of the methods used to minimize exposure of the gum to the peroxide solution.

"How much misalignment does there need to be on a stamp for it to be considered an error?" Perf shifts are known as freaks rather than errors (if the perforations were missing then it would be an error - called an imperf). The onre you have pictured is merely poorly centered and thus less valuable - in order to make it to the freak category, the perforations need to be completely inside the stamp design - the further the better).