dict.cc says:

http://www.dict.cc/?s=origin%C3%A4r

An artist should not be original but rather originous.

I guess I didn't understand your question, escoville. Are you looking for a way to make the whole sentence work?

>?> An artist needn't one up, but should be a one-off.

My question was: can anyone think of a way of translating originär and originell that captures the meanings pithily and preferably in similar words.

Todd has suggested a word which as far as I can see doesn't exist; tastymorsel's suggestion is interesting (and hits the nail on the head), but I fear is stylistically inappropriate.

originell
Adj.
Aussprache:
Herkunft: Latein
1. ursprünglich, in seiner Art einmalig ⇓
Anzeige schließen ein o. Künstler, Gelehrter
ich ... habe ihren originellen Charakter ein wenig kennengelernt, wenigstens den der Kohlenbergleute — Kisch Rasender Reporter 15
2. eigentümlich, durch seine besondere, oft komische Art auffallend ⇓

even though the first definition of "originell" given in the DWDS is the same as the only definition for "originär", namely "ursprünglich", I wouldn't have thought it still is its primary meaning. It's more like "funny, novel (as in novelty gadget)" etc.
So something like "an artist shouldn't be fancy, but original" - but I don't know how you could keep the Gleichklang of the original.

a stab in the dark

An artist doesn't have to be unique, but his works should be ?

not necessarily original but the originator/(original) source?

Perhaps a mixture of "genuine" and "origin" to explain the contrast?

but he should be genuine! appeals to me - not the first part... uniqueness comes into it somewhere - like does not have to be totally/completely original - just think of series of paintings ... like say Monet's garden are variations on a theme - all genuine Monets

An artist doesn't have to be unique, but his works should be genuine ?

Nr. 8 hätte natürlich ingenious sein sollen und nicht "ingenuinous".

Mea maxima culpa.

#11 ... as opposed to copies of someone else's work - inspiration is a different matter - original interpretation - think 10 students drawing the same model...

again, I don't think the author meant "originell" as in original, but more as in "ein originelles Faschingskostüm" - i.e. witty, interesting, different. It just looks the same as "original".

only btw. 1000 x Seerosen zu malen ist auch nicht gerade orginell... wenn vielleicht auch schön

here is some hand-made stuff

Another try escoville: An artist doesn't need to be distinguishable, but rather distinct(ive).

The German sense of "eigentümlich, durch seine besondere, oft komische Art auffallend" (#5) can come across in the English adjective, too; and it certainly does come across in the English noun: "he's an original".

"originary" exists.

"An artist needn't be original, but should be originary."
"An artist needn't be original, but should be an origin."
"An artist needn't be an original, but should be original."
"An artist needn't be an original, but should be originary."
"An artist needn't be an original, but should be an origin."

etc.

*yawn*

Or "seminal"?

"An artist needn't be original, but should be seminal."

Ein Künstler muss nicht originell, sondern originär sein

an artist need not be original but creative.

yet another interpretation

"An artist needn't be an original, but should be original."

that's it!

Das wage ich aber zu zweifeln.

*edit*

Höchstens so etwas wie:

"An artist should be original not an original."

you doubt my statement or the original (:-) statement?

(psst, btw. it's bezweifeln in this phrase.)

edit: a-ha, I see what you mean. I was just so relieved to see someone at last going into the right direction...
yes, the translation in #20 is even better.

Ich meinte, die (meine in #17 von Dir zitierte) Formulierung ist höchst unschön. (Danke fürs 'türchen.)

*edit*

Hätte eff5en sollen.

#19-#22. I don't think that's really the meaning. Pardon me for saying. And I think the task it to try to use two similar words, instead of repeating "original". Again, pardon.

escoville is a highly experienced translator and will come to a good decision. We're just here to throw out a few ideas.

#24 agree

... mein Versuch:

An artist doesn't have to be ordinar(il)y pleasant but (to be) pleasantly extraordinary ? . . .

This thread seems to have grown while I was looking the other way. Thanks everyone.

I decided that some of the suggestions, while "original", were original in the sense that the writer said an artist shouldn't be. (Actually I think his sentence committed the same error.) I said: "An artist should be original, but not in the sense of 'clever'", which is bland perhaps, but not "clever". I left readers to work out what other sense "original" might have, it's not difficult.

Footnote on an amusing translation embarrassment: later in the text, the same author discusses the concept of "blackness". He adduces a poem by Wallace Stevens, which includes a line which he thought was translated into German thus:
Die Farbe ihrer Schwärze...

Unfortunately the poem is about peacocks, and the line in English is "The color of their tails" (Geddit?)