What is Character sheet? Definition, key points and related tools

SinCoSphere EditorialUpdated 2026-09-123 min readTerm

A character's reference image: pure white background, frontal full body, key + fill + rim light, neutral expression, 9:16. The goal is recognisability, not beauty — any baked-in mood or lighting is inherited by every shot.

An animation model sheet, rewritten for a machine reader

Animation, comics and games use model sheets to standardise a character's appearance, poses and gestures when several artists draw the same figure. In AI drama the artists are separate model calls, and the sheet does the same job with one difference: it is read by a model that copies what it sees. An animator's sheet shows many expressions and poses because a person knows they are options. A reference sheet shows one calm frontal state, because anything on it becomes the character's default in every shot.

One frontal sheet, or a multi-view set?

It depends on how the video model counts references. Kling's Element Library builds one element from 2 to 4 images and recommends a front-facing main image plus 1 to 3 supplementary angles, so extra views are cheap there. Per-image systems such as MiniMax H3, Seedance and Wan count every image against the call's cap, so a side view competes with another character's face crop, and the face crop comes first. Runway's guidance adds that a single high-quality front or three-quarter reference works for most projects.

Do not pack a turnaround into one tall strip: below an aspect ratio of 0.4, H3 and Seedance reject the file. Supply views as separate images.

Resolution: where the face pixels go

A full-body 9:16 sheet spends most of its pixels on clothes. A worked example: BytePlus lists 1600 × 2848 among its 9:16 sizes for Seedream. If the figure fills about 90% of the height and is 7.5 to 8 heads tall (the figure-drawing convention for an average and an idealised adult), the head is roughly 320 to 340 pixels tall. A face crop from it clears the minimum input sizes that Vidu, Alibaba, MiniMax and BytePlus list (128 to 300 pixels per side) but falls well short of the 1,024 pixels on the shortest side that Runway recommends for character references.

Two fixes: generate the sheet at the model's largest 9:16 size and crop from that, or derive a head-and-shoulders image from the approved sheet with an image-editing model, so the face is carried over rather than re-invented by a fresh text-to-image call. Most of Alibaba's Qwen image-editing models accept one to three input images for this kind of edit.

Acceptance checklist before a sheet enters the cast library

Face unobstructed: no hair across the eyes, no sunglasses or hat unless it is the character's fixed anchor.
Hands empty and relaxed. A prop held in the sheet tends to follow the character into every shot.
Head to feet in frame, nothing cropped.
Flat white background: no floor set, no text, no logo, no watermark. Seedream adds a watermark unless the watermark parameter is false.
Matches the appearance text item by item, including the one static anchor.
Fits the target model's window: aspect ratio 0.4 to 2.5 for H3 and Seedance, no transparency for Wan 3.0 (see reference image).
Stored and versioned. Seedream output URLs expire after 24 hours; keep your own copy, labelled with a version and the episodes it covers.

Common mistakes and their causes

A glamour portrait instead of a sheet. Dramatic light, a smile and a leaning pose are copied into every shot and then fight the storyboard's lighting.
Regenerating to fix one detail. A new text-to-image call is a new person. Edit the approved sheet instead, and do the same for extra outfits: one sheet per look, same face.
A photo of a real actor. Seedance 2.x does not accept directly uploaded references containing real human faces, and OpenAI's Videos API (scheduled to shut down on 2026-09-24) rejects input images with human faces. Use generated characters or rights you hold (see the rights checklist).
Using the sheet as a first frame. The clip opens on a studio pose and, on H3 and Seedance 2.5, takes the sheet's aspect ratio. Sheets belong in reference slots (see first / last frame).

Key figures and sources

Figure	Value	Source	Date
Model sheet (animation, comics, games)	standardises a character's appearance, poses and gestures across artists	en.wikipedia.org	2026-09-12
Kling Element images	2–4 per element; front-facing main image recommended	kling.ai	2026-09-12
Runway character-reference guidance	at least 1,024 px on the shortest side; one person; front or 3/4 view	runway.com	2026-09-12
Seedream API defaults (BytePlus ModelArk)	watermark on unless set to false; output URLs valid 24 hours	docs.byteplus.com	2026-09-12
Seedance 2.x image input (BytePlus ModelArk)	aspect 0.4–2.5, 300–6000 px; real human faces not accepted as direct uploads	docs.byteplus.com	2026-09-12

FAQ

Should the sheet be 9:16 if the drama is 16:9?

Yes. The sheet's shape serves the full-body pose and sits inside the 0.4 to 2.5 input window of H3 and Seedance. In reference mode, pass the drama's ratio explicitly: H3 defaults to adaptive there and picks a ratio from its inputs. In first-frame mode the sheet would set the shape, which is one more reason never to use a sheet as a first frame.

How do I give a character a second outfit?

Make a separate sheet for the new look, derived by editing the approved sheet so the face carries over, and bind each look to the episodes where it is worn. The character consistency guide covers looks per episode.

Can I use a photo of an actor as the sheet?

Not without the rights to that person's likeness, and some models refuse it anyway: Seedance 2.x rejects direct uploads with real human faces, and OpenAI's Videos API, until its scheduled shutdown on 2026-09-24, rejects input images with faces. A generated character avoids both problems.