Craftspeople in the printing industry commonly create something called a "proof" as a color reference guide for adjusting the press before the final press run. The primary goal of proofing is to serve as a tool for customer verification that the entire job is accurate.

A basic 4th Edition Balance artist proof. Most all artist proofs are signed upon delivery to the artist and are easily distinguishable by their plain white backs.

Each one of these probably individually claim a decent chunk of the total number of Royal Assassin APs out there. These do not belong to me btw, but if you happen to have an Assassin AP laying around, feel free to contact me and I'll get you in touch with the collector :)

I rarely get envious of other peoples' stuff, but these mesmerize me. My wife even gave green light to put them up on the living room wall if I eventually get my hands on a set of these :P

Square-cornered Limited Edition proof, here with a sketch on the back by Mark Tedin.

Boom! A global set of Juzam Djinn; light and dark printings. I guess I should find the oversize as well though. And a signed one. And all the promotional material with Juzam on it. And perhaps cards like Plague Sliver. Hmm. Slippery slope after all.

Shamelessly stealing this image from the Artist Proof page on Facebook.

Here's a stupid but amusing oddity though. It is not an Italian The Dark artist proof (as there were none), but rather a strange misprint. A common sheet from The Dark was accidentally printed without backs. So collecting a Global Set of Giant Sharks is a surprisingly hard endeavor, considering it is a common with a single printing. Not only is it a Tom Wänerstrand card (which makes the English AP very hard to find), but you probably also want this one (and of course one from winning n00bcon ;)).

6th Edition Llanowar Elves proof with alter by Anson Maddocks. Much love to Domenico Megu Chionetti for this one <3

Tiny original oil painting on the back of a Liliana of the Veil artist proof, by Steve Argyle.

If you know these four cards by heart, you get two old school points. No cheating ;)

Printing is craftwork. The printing machines used at Carta Mundi were Heidelberg presses; huge constructs the size of a room. Card images were submitted on film and then deconstructed by hand before being etched - separated by two layers and four colors - into a printing plate. Colors were added and dried one at a time, and even things like the weather could affect the ink and how the card turned out. You had to think about a lot of things to create a high-quality product. Dot-gain, bubble spots, typesetting, layout and how to apply the varnish finishing to mention a few. Like with any art, you really want to do a proper rehearsal before releasing your product to the general market.Since the early days of magic, the last proofs before the general printing of a set were given to the artists responsible for the art on the card. Or at least the artist credited for the art on the card. It seems highly likely that e.g. Drew Tucker got the proofs for the Plateaus in Revised as well due to the misattribution.There are a few different ideas on why the distribution of artist proofs in Magic started and why it looks like it does. Regardless of which story we take as the truth, we can surely say that it is a fun type of business card, and a treasure to hunt for for those looking to complete a global set of particular cards.Today the artist proof deliveries are fairly streamlined. A majority of the "bulk" newer ones can be found for a small handful dol lars by contacting the artist or an agent, while the truly iconic ones - even from the current era - can cost and arm and a leg.Going back to our modus operandi though, things get a little more convoluted. For the sets before Chronicles, most bets are off for the actual numbers. The numbers I state in this post are the closest to proper data I have been able to find, but print numbers were not written in stone during the first few years. A few cards may have had over a hundred copies, and another might have had a few or none. E.g. Douglas Schuler received 30 of almost every proof for Limited Edition except Mountain, of which he got over a hundred of each version. Some other sources also claim that his first Serra Angel proof were surprisingly rare. Supposedly something happened on their way to Schuler, and he only received 15 of them.Another guy who throws the stats out the window is Tom Wänerstrand. Word on the street is that he wasn't interested in proofs and simply threw pretty much all of them away when he got them. That makes collecting a global set of, say, Royal Assassin, astonishingly hard and one of the more back-breaking endeavors a collector might set out on.Regarding some of the earliest artist proof there are still debates going on about their origin, in particular for the very first editions of Gathering. There seems to be some sort of consensus that the Alpha "proofs" were simply ordinary Alpha cards received by Peter Adkinson at Origins 1993; identical to the rest of the set with normal Magic backs. There is also a common understanding that there were no proofs made for Unlimited Edition. The main challenge is Beta.One theory states that the Beta proofs were never cut up. Instead WotC took the whole sheets and gave them out as such. 14 were supposedly give to the inner circle at Wizards, two were given out as top prizes in tournaments, one were framed at the WotC headquarters, one was cut up to play with, and perhaps a small handful more were lost to time.Another theory states that the Beta proofs were indeed cut up and distributed, with a varying number of proofs given out to each artist (common estimates of the first batch is 30-50, with some outliers like the Mountains mentioned earlier). These proofs were however square cut, unlike all other proofs to come after this first printing.Both these products certainly exists. I own square cut Limited Edition proofs, and that sheet up there belongs to a friend in Oslo who got it from one of the original WotC employees. The question is rather which one of these printings can be considered "Beta proofs" and which is a part of CE/IE. The most popular story however - which notably is shared by Magic's first art director Jesper Myrfors and artist proof black belt Mark Aronowitz - is that the square cornered ones were made for Beta.Regardless on what set they were actually printed with (or for what purpose) we can in good conscious say that these square cornered prints are the first batch of proper artist proofs. I personally mostly refer to them as Limited Edition proofs, as they are certainly that.Next set to enter the stage was Arabian Nights. This set was somewhat rushed to market, and no proofs exists. This makes collecting global sets of AN cards comparably easy.AQ went a little further than previous sets and made about 100 proofs for each card. Though this was also kinda random ("wack" to quote a guy in the know), and some cards had print runs of over 200. Seems like I keep running into Energy Fluxes.Revised went back to 50 of each proof, but started making proofs for multiple languages to compensate. Not all languages though, that would be far too simple. So Revised had 50 proofs for the English version of each card, and an additional 50 Italian. No German or French versions are known.After giving a nod to the Italian crowd with Revised, WotC went back to English only for Legends. They kept the total high though, with at least 100 proofs for each card. For The Dark, they again dropped back to around 50, still keeping it English only.That brings us to the end of our journey for the "Swedish legal" sets. We can note that FE went back to around a hundred of each proof, and 4th then sailed down to 50 of each version again, but went for a higher total due to more languages represented (50 each of wb English, wb Italian, bb Japanese, bb Traditional Chinese, and still no love for French or German. Or Portuguese, Spanish, or Korean for that matter.)Alters on the front of proofs are comparably not that common, but sketches - or even proper artwork - on the backs have become a cool way for artists to show off their skill. As you mainly get proofs directly via the artist, the blank backs are great to commission art on. Some of them are wild, with detail comparable to the actual art on the front.For us more entrenched in the mid 90s, a good chunk of the original artist are also up to colorful alterations on their old proofs these days. Here is a sweet playset from Antiquities courtesy of Jeff A. Menges.So that's artist proofs for you. Are they legal to play with, you ask? Well, certainly not in sanctioned tournaments, as they don't have the standard Magic back nor were made to be played with. I would however presume that nobody would punch you if you showed up with them at an EC-rules 93/94 tournament, though always best to check with the organizer first. I can't imagine that any of the rule sets that allow CE/IE would frown upon this kind of collectible card stock. And I know of at least one guy that sneakily played proofs at a n00bcon a while ago. Technically not legal here as they are not "real cards", but I don't have the heart to be a douchebag about everything ;)I'd like to give an extra shout-out to Mark Aronowitz who assisted with some additional info about the earliest proofs, and helped looking over the numbers. Check out the artist proof group he administrates on Facebook if you want to dig deeper or get in contact with some collectors.If you are hankering for some more 93/94 Magic content, let me suggest that you check out this properly old school report from the fourth Knights of Thorn , courtesy of Carl from Belgium.