This is the 15¢ Landing of Columbus stamp from the 1869 pictorial issue.
There are two types of this issue. Type I is Scott #118 and Type II is Scott #119. So what’s the difference?
There are several tiny differences. But to me, the easiest difference to see is in the small triangular area at the top center of the vignette and just below the “T” of “POSTAGE”.
In Type I (#118), the triangular area is not filled in. There may be a few tiny and very light horizontal shading lines present under magnification. But to the naked eye, the triangular area will look bare. There is no outer brown frame line around the blue vignette. There are only some tiny brown, horizontal shading lines that are between the blue vignette and the brown tablet area of the stamp.
In Type II (#119), the triangular area is filled in. There is a thin, but solid brown frame line around the blue vignette. When the frame line comes together at the triangular area, there is a small diamond shape formed. To the naked eye, the triangular area is filled in.
At this writing, a used copy of Scott #118 is $800 and a used copy of Scott #119 is $250. So Scott #118 is about three times more valuable than #119. Similarly, mint no gum copies catalog $3500 and $1200 respectively.
If you’re diligent, you can sometimes find a copy of Scott #118 that someone misidentified as Scott #119. Who doesn’t like to find a more valuable variety of a stamp when the seller wasn’t careful to correctly identify their material.
The reverse can be true too. If someone is offering you a Scott #118, make sure you’re buying a true #118. You don’t want to overpay for a misidentified #119.
For completeness sake, there is a Type III. This type is only found on the 1875 reprint of the 1869 issue. This is Scott #129. Type III is like Type I except that the thin brown horizontal shading lines that surround the blue vignette are gone. There were only 1981 copies of Scott #129 issued. The catalog value is $1350 mint and $1250 used. Most collectors are not likely going to encounter Scott #129. But if you do, it is a Type III.