This question links "painter-poet" to Edmund Spenser, basically asking if Spenser is adept at using imagery—for a painter-poet would be best suited to write in such a way that his descriptions would be realistic and precise, as if we could picture in our minds the exact sequence of events, character's features or landscapes described simply through the author's words.
While the language is somewhat different than modern English,(especially noting that "u" and "v" are sometimes switched), with persistence an image comes to mind—with strong detail. In the following, Spenser effectively uses the color white in his description. Recall that this is not just what he wants his reader to see, but also what he wants us to understand: she is purity and goodness...white is symbolic of these things. This is about noting the details of her physically, emotionally and spiritually:
A louely Ladie rode him faire beside,
Vpon a lowly Asse more white then snow,
Yet she much whiter, but the same did hide
Vnder a vele, that wimpled was full low,
And ouer all a blacke stole she did throw,
As one that inly mournd: so was she sad,
And heauie sat vpon her palfrey slow:
Seemed in heart some hidden care she had,
And by her in a line a milke white lambe she lad.
So pure and innocent, as that same lambe,
She was in life and euery vertuous lore...
Translated, this means that beside the Red Cross Knight rides Una—a lovely young lady. She is seated on the back of an ass (humble—as Christ road into Jerusalem the Sunday before his death). While the animal is white, she is even paler—as seen under her veil and wimple, and in contrast to the black stole she has thrown around her. (Overall, however, the scene lacks color.) The narrator notes that she is pale not only by contrast to what she wears, but also because she is mourning inwardly ("inly")—we will soon learn why she is so desperately sad. She sits heavily upon the animal—as if there is a hidden burden she must carry. And beside her walks a line of equally white lambs—she is as pure and innocent as those lambs.
Spenser "paints" a picture of a woman who is heavy-laden with sadness and overwhelming worry; but there is a goodness and purity about her also. Spenser presents her effortlessly to the reader.
As a poetical painter, using words and rhythms in the place of external form and colour, [Spenser] is, perhaps, unrivalled.
His descriptions of what they pass in the forest are lyrical and alluring:
And foorth they passe, with pleasure forward led,
Ioying to heare the birdes sweete harmony...
Even the air in this fairy realm seems beyond the realm of the human world:
An ampler ether, a diviner air...
Spenser is a poet in the purest sense of the word. It is not just his rhythm or rhyme: for other less-skilled writers can copy these poetic devices. Spenser has an imagination that creates magical places that we can see in our minds: equally clear are the pictures of the people and the landscapes around them created by language. Spenser is certainly more than able to use words to create outstanding images—as a "painter-poet"—to make his writing come alive to its audience.