One specific question I have is: do his individual works stand alone or do you have to understand his life and/or complete body of work and the context in which it was created to appreciate it?
If you saw one or two of his paintings without ever having heard of Jasper Johns would you recognize them as masterpieces?
Really good art is often both striking without any foreknowledge, but also reveals extra complexity when you learn about the context in which it was made. When you look at a piece of non representational art, before you know the artist, try and think about the choices the artist made, and why they made them. Why is this line a certain thickness here, why is this part more or less transparent?
The process of making any piece of art is a series of decisions, conscious or not and at least to me, non representational art is an attempt to distill that part of creation into a physical form.
Your experience of food, wine is a function of your prior experience (and -- most importantly -- interest) w/ food & wine. Never had much wine before (like me), and you'll shrug w/ indifference at every glass. But this is only (my) ignorance/lack of interest/etc. It's a lacking.
Likewise, if your experience engaging w/ a painting on canvas is limited and mostly of disinterest/disengagement then so much of any given painting is going to be lost on you. Not completely, but by a large margin it will be.
The last question about recognizing the painting as a masterpiece is a little misplaced or needs fleshing out... No one looks at a painting and categorizes it as masterpiece or not. What one does is look at a painting and is given an experience and range of emotion. If that emotion is intense -- eg, exhilarating or intriguing or aggravating -- then the next question will be -- do I think this is a universal reaction? (I.e., not idiosyncratic to me. Experience guides in answering this follow-up, of course.) Then, if so: does this artist have an agent? Could I be his/her agent (if you think about making $$ alot)? OR: surely this piece is already established its market, ie been established as a Masterpiece by prior or current culture. Anyway what strong emotion typically does in any flesh & blood human is inevitably send us racing after questions like these..
But no, you don't need to understand "his life and/or complete body of work" to enjoy it.
From my perspective, I'd say it's really more important to know where an artist's work stands in relation to their culture and their contemporaries. Most important artworks can be seen to have extended previous practice, to have influenced subsequent practice, and/or can be seen in retrospect to belong to some coherent zeitgeist.
You may see some works to truly stand alone. But I've personally found it difficult to connect to most great artworks that way.
Maybe food is a good analogy? (another art form that goes back to Homo Sapien origins).
I appreciate a cake that my daughter makes from a box. But, I really, really appreciate a cake made by a master baker - a unique creation where every aspect (taste, texture, design, display, temperature, flavor, etc.) is considered and balanced into a cohesive whole.
The Wikipedia article on abstract expressionism actually comes right out and says as much. So I'd start there, if you want some contextual background.
He used encaustic, which is a mixture of hot wax and oil paint, which lends the paintings a really unique texture. There's also often newsprint embedded in the paint, which adds another layer of texture.
Reproducing the American flag in this medium, and at scale, offers all sorts of questions. The red drips are maybe too symbolic, but the embedded newsprint gives a sense of history, and the whole handmade effect just adds to the ambiguity.
I once read some of his sketchbook notes, in which he'd written something along the lines of "try to hide what's going on from the viewer." So, he was being deliberately vague. And somehow it works, at least in his early works.
The narrator described 'Flag' as many things: a flag, a painting, a sculptural object, a commentary and a concept.
These were and remain all true and equally valid.
The historical context of mid-50s America is helpful but not essential. Of more relevance is the disruptive innovation of creating a work both of and outside the system, that ends up influencing the system in return.
It's like a self-aware mutation with genetic and memetic qualities.