Sarah Clarity Studios

Chapter 1: Blade Anatomy & Balance

Created by Sarah Choi (prompt writer using ChatGPT)

Blade Anatomy & Balance (Fuller, Spine, Tang, Guard)

Edged weapons read as body, not gadgets. Their credibility comes from proportion, balance, and the way parts meet. For weapon concept artists—both on the concepting and production sides—understanding blade anatomy turns ornament into structure and keeps silhouettes honest under motion. This article focuses on swords, knives, and daggers from a depiction‑only standpoint: how to see and communicate form, not how to fabricate or sharpen.

The anatomy map at a glance

Most blades can be described with the same vocabulary: point (tip), blade (body between point and guard), edge (cutting face), spine (back opposite edge), fuller (longitudinal groove or hollow), ricasso (unsharpened neck near the guard), guard (cross, quillon block, or integrated bolster), tang (portion passing through the handle or scales), grip (handle), and pommel (terminal mass or cap). The scabbard or sheath adds throat, chape, locket, and suspension fittings. Your goal in concept and production is to show how these modules relate, where hands live, and how loads travel—without giving construction steps.

Balance: center of mass, pivot points, and harmonics

Balance is what the audience feels even through a screen. Three landmarks matter for depiction: the center of mass (CoM), the forward pivot point (where light cuts feel to hinge), and the node near the grip (where vibration is least felt). Long cutters that prioritize reach place CoM further from the hand and show proportionally larger grips or pommels to mediate inertia. Quick point‑control blades bring mass back with thicker tangs, denser pommels, or narrower tips. Show balance with proportion cues: pommel volume, fuller depth and length, distal taper (thickness reduction toward the tip), and cross‑section choices.

In animation, balance reads as how quickly the weapon starts and stops, how much follow‑through the tip demonstrates, and how little the hand must travel to redirect the edge. In production, hold consistent CoM approximations by keeping wall thickness and pommel mass relationships stable between views.

Fullers: stiffness, mass, and visual rhythm

A fuller is not a “blood groove.” It is a hollow that lightens the blade while maintaining bending stiffness, much like an I‑beam. Depict fullers as consistent channels with clean terminations—often fading before the point or guard for structural sanity. Their width, depth suggestion, and count define rhythm along the blade. Fullers are common on longer swords; on knives and daggers, shallow hollows or swages can serve similar visual roles. Avoid placing fullers where they would collide with guard slots or screw into thin tips; keep terminations believable by echoing cross‑section transitions.

Spine: the load path anchor

The spine carries most bending load. Its thickness profile (distal taper) and edge geometry together set the blade’s attitude. Flat spines read utilitarian; bevelled or crowned spines imply stiffness and refined handling. On double‑edged blades, the “spine” becomes the central ridge; on single‑edged blades, the spine is the back. Use the spine to cue balance: thicker near the guard for control, thinning toward the point for speed. Texture and finish along the spine also guide light; a matte spine reduces glare into the user’s eyes in stealth‑oriented sets.

Cross‑sections: what silhouettes cannot tell

Cross‑section governs both structural behavior and reflected light. Common families include lenticular (almond), diamond, hollow‑ground, flat‑ground, and wedge variants. Lenticular reads soft and historic, diamond emphasizes a central ridge and crisp planes, hollow suggests cutting bias with reduced mass near the edge, and flat keeps machining‑friendly reads. For daggers, diamond and hollow dominate; for knives, flat and hollow are frequent; for swords, lenticular and diamond are principal. Choose a family and remain consistent across orthos and paintovers so shading and edge highlights agree shot to shot.

Edges and bevels: surface truth without procedure

Edge geometry (not sharpening) defines how light collapses at the margin. Single bevels read robust and tool‑like; compound bevels read refined; micro‑bevel hints at maintenance. Depict shoulders where bevels break, keep transitions clean, and avoid razor‑thin highlights that would vanish at gameplay distances. In production, plan where normal maps carry micro‑bevels and where geometry must hold profile, then keep these decisions consistent at all LODs.

Ricasso and choils: control and clearance

The ricasso is an unsharpened neck near the guard that improves control and accommodates guards or bolsters. Some knives include a finger choil—a relief notch near the edge that signals a close grip. Show these as deliberate breaks in edge continuity with enough clearance for fingers or guard fittings. In animation, they provide safe, readable hand placement; in modeling, they anchor parting lines and material IDs for guard and grip transitions.

Guard families: protection, index, identity

Guards protect hands and index grip orientation. Crossguards with straight or slightly downturned quillons favor blade alignment reads; discs and tsuba‑like plates emphasize rotational index; integrated bolsters on knives produce seamless, robust joins. For stealth doctrines, guards stay compact; for ceremonial doctrines, guard faces become ornament focal points. Keep sight corridors clear; no quillon should obscure line‑of‑attack in first‑person frames. Model guard‑to‑ricasso interfaces as honest seats with visible shoulders rather than floating, and ensure guards do not intrude into hand envelopes.

Tang architectures: what the handle must hide

The tang is the hidden continuation of the blade into the grip. Depict tang families without giving build steps: full tangs (visible between scales), hidden/encased tangs (buried inside a guard and grip), and partial tangs. Full tangs signal rugged, serviceable tools; hidden tangs support ornate or shaped grips without visible metal edges. Show tang logic through grip silhouettes and fastener language—not with assembly instructions. Keep proportions believable: a blade that promises heavy leverage should not be paired with an implausibly tiny tang silhouette.

Grips and pommels: ergonomics and mass tuning

Grip geometry must respect hand anatomy and gloves. Indexing swells, flats, or facets cue orientation; textures provide traction without over‑greebling. Materials tell stories—wood and leather suggest craft lineage; polymer scales suggest industrial production; cord wraps imply field expedience. Pommels cap the system: they tune balance and provide termination for attachment (lanyards) or simple end protection. Read pommels as mass statements—more volume moves CoM back; faceted caps light differently than domes; through‑pins or peen heads visually fasten without detailing process.

Scabbards and sheaths: the other half of the silhouette

Carriers explain how the blade travels. Scabbards show throat geometry, locket placement, suspension points, and chapes that protect tips. Sheaths reveal welt thickness and stitch logic; modern sheaths telegraph tension‑fit or latch features. Keep draw corridors and retention reads clean. For production, define strap routing and snag risk; for concept, show a standard open case or scabbard interior to teach what “complete” looks like in your world.

Material and finish reads

Steel variants read through polish and oxide; pattern‑welded steels present figure that should follow geometry honestly. Ceramics imply edge stability but brittleness and appear matte with crisp, unrolled highlights. Composites and exotic inserts belong on grips, guards, or scabbards; keep edge‑bearing parts true to credible materials in your setting. Finishes age in characteristic ways: bluing polishes on high points, patina creeps from moisture traps, leather darkens where hands ride, cord wraps smooth on corners. Provide micro‑swatches for shader teams and keep values disciplined for gameplay readability.

Fieldwork: learning to see load paths

Museums, living‑history events, smithies, and maker spaces teach how blades really meet grips and guards. Sketch thickness changes, tang silhouettes guessed from X‑rays or exposed examples, guard shoulders, and peen treatments. Log exhibition restrictions, obtain permissions for close photos, and default to sketching when photography is limited. Observe wear polish on scabbards where belts rub and where hands repeatedly contact—these maps help texture artists tell a truthful story without procedural notes.

Research ethics and cultural respect

Keep your study and depiction within ethical bounds: no construction, modification, or procurement guidance. Attribute sources, obey venue rules, and separate restricted imagery in your reference library. When borrowing motifs from living sword traditions, consult practitioners, credit lineages, and frame ornament with respect to cultural contexts. Avoid copying unique maker signatures; generalize design principles and re‑express them in your world’s language.

Anatomy sheets that teach at a glance

Pair each hero blade with a one‑page anatomy sheet: hero side view; a small cross‑section band at three stations (near guard, mid‑blade, near tip); a human‑factors overlay showing grip zones and safe edges; and labeled modules—spine, fuller, bevels, ricasso, guard, tang (silhouette only), grip, pommel, scabbard fittings. Use restrained color coding (green = hand zones, red = hazards/motion, blue = alignment/flow). Keep captions descriptive and depiction‑only.

Concepting guidance: silhouette families and balance targets

Start ideation by choosing a balance target (reach‑biased, neutral, tip‑light) and a cross‑section family. Define fuller logic and guard family early; these choices lock rhythm. Explore ornament only in focal zones (guard faces, pommel caps, scabbard throat) and keep hand corridors quiet. Provide three variants that change just one variable at a time—cross‑section, fuller length, or pommel mass—so reviews see deliberate tradeoffs. Paintovers should use consistent highlight rules to preserve edge credibility across frames.

Production guidance: topology, trims, and LODs

Model edges with controlled bevels that survive bake and distance. Reserve geometry for silhouette and cross‑section; push texture detail for micro‑bevels and etch. Build trim sheets for rivet rows, braids, and simple inlay carriers; keep pitch bands consistent so arrays compress gracefully at lower LODs. Maintain CoM approximations by preserving wall thickness and pommel mass relationships across LODs. Provide exploded but non‑procedural callouts for part boundaries (blade, guard, grip, pommel) to aid material ID and shader assignment.

Animation and audio hooks

Design draws and resheath beats around clear geometry: scabbard throats that guide, guard shapes that clear, choils that index. Audible cues match materials—leather creak, metal ring, muted polymer thunk—recorded or synthesized ethically. Motion arcs should respect your balance target: tip‑heavy designs show more follow‑through; neutral blades redirect crisply. Provide a tiny cadence map per weapon—beat labels like draw‑index‑settle—to keep cross‑discipline timing aligned.

Case sketches across types

A long cutter with extended fuller, lenticular section, modest downturned crossguard, and domed pommel reads as reach‑biased but controllable. A thrust‑centric dagger with diamond section, shallow ricasso, small disc guard, and heavy flared pommel keeps CoM back for point control. A field knife with flat grind, crowned spine, integrated bolster, and full tang scales telegraphs utility and serviceability. Each uses the same vocabulary to say something different about balance and purpose.

Final thought

Blade anatomy is a grammar of load paths, hand safety, and light. When you commit to balance targets, cross‑sections, and honest joins—and communicate them via clear anatomy sheets—you give both concept and production artists rails to build on. The result is edged weapons that read as credible tools of their worlds, animated with intention and textured with truth—without ever teaching construction.