This style guide is meant to help ensure card production looks like it's all part of the same game. Most of these standards are simply "this is what WotC did", with a little bit of "the community introduced this concept, so this is how it should be displayed".

To be clear, this is all in regards to a card's appearance and look, and has no bearing on a card's mechanics or how powerful it is. Jihen does have a useful guide for that though.

Card Size & Filetypes
All cards should be 300 DPI, and have a 50px bleed. Many professional printers require at least a 3mm (35px) bleed around the edge, but since some require a little more we increase it to 50px (4.23). Using Hasbro's official sizing as a base, the chart below shows all our sizes, with and without bleed.

              300 DPI w/ Out Bleed           |  w/ Bleed      
Small:         63 x  88 mm    744 x 1039 px  |   844 x 1139 px
Standard:      88 x 126 mm   1039 x 1488 px  |  1139 x 1588 px
Large:        143 x 200 mm   1689 x 2362 px  |  1789 x 2462 px
L. Folded:   71.5 x 100 mm    844 x 1181 px  |   944 x 1281 px

• S. Folding and L. Folding are the exact same sizes as Standard and Large, respectively.
• S. Folding folds in half to become Small.
• L. Folding folds in half to become L. Folded

Note: The individual pieces of a folding card (like the bot & alt mode on a combiner piece) should also have each of their pieces with full bleed. So, to use a standard sized triple changer as an example, you'd have four images:
Alt Mode 1 & Alt Mode 2 would each have small images w/ bleed.
Bot mode would be a standard sized image w/ bleed.
Then there's the folding image of the card, with Alt1 & Alt2 on it, that's standard size with bleed.
As a reminder, that means the two individual small-sized images won't exactly fit on the standard sized image due to the bleed they each have.

For reference: All cards on Transformers.cards are stored with bleed, then the bleed is automatically cropped out when they're displayed on the site. This is to facilitate printing, as it's easier for the script to crop bleed out than it is to store bleed & non-bleed versions of cards.

Art
Official Hasbro art is fine to use without any need for permissions. This includes images from licensed comics and marketing materials. All fanart requires explicit permission from the artist to use it. Commissioned art does not require permission from the artist, but does require permission from the commissioner.

Artwork made for 3rd Party packaging/manuals may be used without obtaining permission, since the company themselves are infringing on Hasbro's IP. HOWEVER, be a bit knowledgeable on which 3rd Party companies you use art from. While most of the "big name" 3rd Party companies do use original art, some of the knock off companies will use stolen art.

Do not use poor quality images. To elaborate, this is not remark on the quality of the art, but of the image file itself. Avoid images that are very grainy or blurry. Upscaled JPEGs with artificating look very ugly as cards.

When adding art for the Card Image Generator to use, make sure it's sized accordingly.
Battle cards: 696 x 514 px
Characters: Full size with bleed (see sizes above)
Small Stratagems: 692 x 550 px
Other Stratagems: To be determined

Fonts
NOTE: This list is being updated, and will have visuals to show what font is used where.

Cybertronian Text - Ancient Autobot
Card name: Bayformers-TFTCG-Name [/small]WotC used an internal Hasbro font, this is the closest we have available to it
Card subtitle: Bahnschrift Regular
Trait: Bahnschrift Bold
Card type: Source Sans Variable Bold Italic
Explanation text: Source Sans Variable Italic
Ability Text: Gotham Narrow weight=325 Condensed, baseline 7, kerning -0.3, full hinting 30px battle cards, 38px standard char
Card Number (small cards): Bahnschrift Bold, 33px, bolded, no hinting,-2 kerning
Set total (small cards: Bahnschrift Semi-Bold Semi-Condensed, 21px, bolded, medium hinting, 0 kerning
Wave (small cards): Bahnschrift 17px, 12px for version, kerning 0
Wave (standard cards): Bahnschrift 19px, 13px for version, kerning 0
Wave (large cards): Bahnschrift 28px, 19px for version, kerning 0
Credits: Bahnschrift Condensed 14px
Printer notice (small): Bahnschrift Bold Semi-Condensed 14px
Printer notice (standard): Bahnschrift Bold Semi-Condensed 17px
Thanks to Team Bayformers for taking the time and effort to figure these all out and letting others use their Name font.

★ Star Values
★value always goes on the bottom left. On character cards, it goes on whichever side is meant to be face-up when the game starts (typically the alt-mode).

Character cards with 13★ or fewer have them lined up and divided into three groups of five, each separated by a vertical bar ( | ). These bars are visible even if not needed. Example: Sergeant Mirage has 7★, but still had the three sections separated by the vertical bars.

Character cards with 14 ★ or more use numbered stars (stars with numbers on them). These are not broken into sections, and are instead lined up in row. Example: Major Shockwave has 14★, and no vertical lines separating sections.

Non-character cards with 3★ or fewer have them lined up. Non-character cards with 4★ or more should use numbered-stars.

Rarity
Even though we're not opening physical packs, rarity is still required on all cards. It's vitally important for formats like Junkion (where you can only use Common cards), and SR is also used to indicate a specialty/niche card.

C = Common
U = Uncommon
R = Rare
SR = Super Rare

While creating new a new rarity is not strictly prohibited, doing so must serve an actual purpose in the game. So far there has not been a reason to.

Character cards add a T after their rarity, such as CT or SRT. Non-character do not do this; there is no S in front of a stratagem rarity.

Numbering
Battle cards use triple-digit numbering, and all other cards use double-digit numbering. Character cards and stratagems have a T and S in front of their number, respectively.

The total number of that type of card in the set follows in a smaller font.

Promos
Promos have a P in front of their number. All promos use double-digit numbering, including battle card promos. Example: Tandem Targeting System mailed to Energon Edition buyers.

Promos are numbered sequentially by year regardless of type. Example: All-Out Attack is the 11th promo of 2019, despite being the first battle card promo. This numbering resets every year. Additionally, Promos list the year they were released rather than the total number of cards in the set.

Promos are in the subset P of their parent wave. For example, Private Smashdown is Wave 3P and Convex is Wave 5P.

Promos use standard rarity denotation.

Set Icon & IDs
Set icon & ID should usually go in the bottom left of a card. However, if there is instead a ★ value on that side of the card, then they go to the right of the card numbering. Example: Bombing Run has no stars and the set is in bottom left, while Ultra Magnus Armor has 2★ so the numbering is to the right of the numbering.

This holds true for stratagems as well; if the stratagem doesn't have a ★ value, the set goes in the bottom left. Should there ever be a character card without a ★ value, the set would go in the bottom left then too.

Set icons are unique to each wave, and sub-sets use the same set icon as the main wave does. Example: The Devastator Set (Wave 2A) uses the same set icon as Rise of the Combiners (Wave 2).

Granted, the Blaster vs Soundwave Set (and the 35th Anniversary version) do not use the Wave 3 set icon, but I don't believe it was ever officially referred to as "Wave 3A" so that will be considered the exception.

Set icons are also made up of geometric shapes, and are not meant to be exactly representative of the set. For example, a shrunken picture of a bot is not a good set icon.

Factions and Traits cannot share names. Race icons are colored, while trait icons are white with black outlines.

   FACTIONS
Autobot       Decepticon    Mercenary  
Quintesson    Junkion       Unicronian 

   TRAITS
Action Master      Aerialbot            Air Strike Patrol 
Allicon            Battle Master        Battle Patrol 
Beast              Boat                 Car 
Combaticon         Constructicon        Dinobot 
Dreadwing          Firecon              Guardian 
Helicopter         Herald               Insecticon 
Judge              Leader               Me Grimlock 
Melee              Military Patrol      Mini-Cassette 
Motorcycle         Off-Road Patrol      Omnibot 
Plane              Predacon             Pretender 
Ranged             Rescue Patrol        Road Drone 
Seeker             Sentinel             Sharkticon 
Spaceship          Specialist           Sports Car Patrol 
Spy Patrol         Station              Stunticon 
Sweep              Tank                 Tentacle 
Terrorcon          Titan Master         Titan 
Train              Truck                Vehicle 
Weaponizer         Wrecker 

Stratagems
All Stratagems must have a back. Typically, this will simply be a full version of the art from the front of the card. These art-sides have rounded black borders.

Stratagems always have a target. It could be a bot, a trait, faction, "cards with Bold", or even "All Characters".