Render believable metal and gemstones

You already know the standard five-part light model from flat illustration — highlight, light side, core shadow, reflected light, cast shadow. Metal and faceted gems push that model harder than almost any other subject, because they're both highly reflective and geometrically complex, so light bounces in sharp, high-contrast jumps rather than smooth gradients.

• Highlight on metal is small, hard-edged, and near-white — not a soft glow. Metal doesn't diffuse light the way skin or fabric does.
• Core shadow on a curved metal surface is often darker and more defined than you'd paint on an organic form — metal has almost no subsurface scattering to soften it.
• Reflected light matters enormously on metal — a gold band sitting near another gold surface will pick up warm bounce light in its shadow side. This is often the detail that separates a flat-looking metal render from a convincing one.
• On facets (diamonds, gemstones), each flat facet plane reflects light as a distinct, evenly-toned shape — not a gradient. Light and dark facets sit right next to each other with a hard edge between them, like a low-poly 3D render. This is the single biggest adjustment coming from smooth vector shading: resist the urge to blend facet edges together.

Here's the core layered technique you'll reuse for every metal in this course:

1. Base fill. Draw your band/setting shape with a hard-edged brush (or QuickShape) filled with the metal's mid-tone base color. Put this on its own layer.
2. Alpha Lock the base layer. Swipe right on it in the Layers panel.
3. Block in core shadow. With a soft round or soft airbrush brush, paint a darker value of the same hue along the side away from your light source, and along the inner curve of any rounded band. Keep opacity around 60–80% and build up gradually rather than committing one dark pass.
4. Add reflected light. On the shadow side, dab in a lighter, slightly warmer tone right at the edge nearest the shadow's darkest point — this "lip" of reflected light is what reads as metal rather than flat paint.
5. Paint the light side. Use a lighter value of the base tone on the side facing the light, with a soft blend into the mid-tone — metal transitions are narrower/harsher than skin, so keep this gradient tighter than instinct suggests.
6. Add the specular highlight last, on a new Clipping Mask layer. A small, hard-edged near-white (or near-black for a "cold" specular on white metals) mark right where the light source would bounce most directly. Keep it small — oversized highlights read as plastic, not metal.
7. Blend transitions with the Smudge tool using a soft round brush, only where you want a soft polish look; leave some harder edges near facet-adjacent areas for a brushed or faceted metal look.

Per-metal color notes

Rather than re-mixing gold's five tones from scratch every project, save them once.

1. Open the Color panel → Palettes tab → tap "+" → Create New Palette, name it "Metals."
2. For each metal (yellow gold, rose gold, white gold/platinum, oxidized silver), mix and save five swatches: base, shadow, deep shadow, light, highlight.
3. Drag each finished color from the color wheel directly into an empty palette slot.
4. Set this palette as one of your default/pinned palettes so it's one tap away in every new canvas.

Before rendering any faceted stone, you need its structural map — this is the "wireframe" you'll shade on top of. In simplified illustrative form:

• Table — the large flat top facet, the biggest single surface, usually reflects the brightest and most direct light or shows a "bowtie" of contrasting light/dark if viewed at an angle.
• Crown — the upper faceted section between the table and the girdle (the widest point of the stone) — a ring of smaller angled facets around the table.
• Girdle — the thin band marking the widest diameter of the stone, where crown meets pavilion.
• Pavilion — the lower, larger cone of facets beneath the girdle, responsible for most of a stone's brilliance since it bounces light back up through the table.
• Culet — the small point (sometimes a tiny facet) at the very bottom, where all pavilion facets converge.

Illustratively, you don't need optically accurate ray-traced facet angles — you need a facet map that reads correctly: a bright table, a ring of alternating light/mid/dark crown facets, and a darker pavilion silhouette showing through the stone's lower half.

1. Outline. Draw the stone's outer circle (girdle silhouette) with QuickShape on its own layer.
2. Facet map with Symmetry. Turn on Radial Symmetry (8 or 16 segments depending on desired detail). Draw the table circle in the center, then one wedge of crown facet lines and one wedge of pavilion facet lines — Procreate mirrors them around automatically. Use a fine, hard-edged liner brush.
3. Base fill per facet with ColorDrop/Threshold. With facet outlines forming closed shapes, use Selection → Automatic (tap inside a facet to select just that closed region), or drag-and-drop a color swatch (ColorDrop) into each facet region on a fill layer beneath your linework. Assign a light gray-blue base to every facet first.
4. Tonal pass — assign values, not gradients. Go facet by facet and shift each one flat to a value in your diamond tonal scale (near-white, light gray, mid gray, dark gray, near-black), following your mental map from 2.1 based on where each facet "faces" relative to your light source. Adjacent facets should have a clearly different flat tone — the contrast between neighboring flat facets is what reads as "faceted," not smooth shading within one.
5. Add a hint of spectral color. On a Clipping Mask layer set to Add/Screen at low opacity, add tiny slivers of color (a touch of blue, a touch of pink/orange) at a few facet edges — real diamonds split light into small rainbow flashes, and even 2–3 subtle color slivers sell the effect without looking gaudy.
6. Highlight pass. On top, add a few small, hard-edged, near-white highlight marks — usually one strong one on or near the table, and a few smaller ones scattered on crown facets. Keep these sparse; overdoing highlights is the most common beginner mistake and flattens the faceted read.
7. Final linework pass. With your original facet-line layer set to a low-opacity dark gray (not pure black) on top, faceted edges read crisp without looking like a coloring-book outline.

Colored stones use the exact same facet-map-and-flat-tone technique from 2.5 — the difference is entirely in color depth and saturation strategy, since these stones absorb and transmit color rather than staying colorless.

• Sapphire (blue): deep saturated blue base, shift shadow facets toward near-black indigo rather than gray-black — colored stones almost never go to a neutral dark, they go to a darker, more saturated version of their own hue.
• Ruby (red): saturated red-pink base; shadow facets shift toward deep maroon/oxblood; highlight facets can flash slightly pink/white rather than pure white, keeping warmth even at the brightest point.
• Emerald (green): emeralds are typically emerald-cut (step-cut, seen in 3.1) rather than brilliant-cut, so facets tend to be long rectangular "steps" rather than triangular wedges — flat planes stacked toward the culet, each a slightly different value of deep green, with fewer sparkle highlights than a brilliant cut since step cuts show broad flashes rather than pinpoint sparkle.
• General rule for all colored stones: push saturation higher in the mid-tones than feels natural at first — colored gemstones read as "cheap/plastic" far more often from being under-saturated than over-saturated, since real corundum and beryl stones have remarkably intense, saturated color even in a small carat size.

Pearls are the opposite rendering problem from faceted stones — no hard facet edges at all, just soft gradients plus one very specific optical effect: iridescence (called "orient" in pearl terminology).

1. Base sphere. QuickShape a circle, Alpha Lock, fill with a warm off-white or cream base (pearls are rarely pure white).
2. Soft gradient shading. With a large soft airbrush at low opacity, build a gentle core shadow on one side and a lighter zone on the other — keep every transition extremely soft; pearls have essentially no hard edges anywhere except the one specular highlight.
3. The specular highlight. One small, crisp, bright highlight where the main light source hits — this is the single hardest-edged mark on the entire pearl, deliberately contrasting with everything else being soft.
4. Subtle iridescence. On a low-opacity Clipping Mask set to Overlay or Screen, add faint streaks of pink, green, or blue near the highlight and along the shadow edge — real pearls show these colors shifting as the viewing angle changes across the curved surface. Keep it barely-there; too much color and it stops reading as a pearl.
5. Reflected light. A touch of warm bounce light on the shadow side, same principle as metal — pearls sitting in a metal setting will pick up warm or cool bounce depending on the metal beside them.

Three textures come up constantly in jewelry rendering — worth building dedicated brushes for each, saved into the "Jewelry Kit" set from 1.7:

• Metal grain brush: duplicate a soft airbrush, then in Brush Studio's Grain panel, load a fine noise/grain texture at low intensity. Use this for brushed-metal finishes and for adding subtle micro-texture to otherwise-flat metal fills so they don't look digitally too-perfect.
• Facet sparkle brush: duplicate a small hard round brush, reduce its spacing so single taps leave a clean star/cross-shaped sparkle (or import a star-shaped stamp into the Shape panel). Use this for the tiny bright sparkle accents scattered across faceted stones in 2.5/2.6.
• Pavé texture brush: duplicate a small hard round brush and set high scatter/jitter with a fixed small size — a few taps or a short drag lays down a scatter of tiny same-size dots, exactly the repeating small-stone pattern you'll need for pavé settings in Level 3.

After building each, tap the brush thumbnail → Share → Save to Files or duplicate into your Jewelry Kit set so it survives even if you reset default brush sets later.

Bring everything in this level together into one finished, fully-shaded piece:

1. Sketch a simple 4-prong stud setting silhouette (Vertical Symmetry for the prongs).
2. Render the setting in yellow gold using your full 2.2 technique and your saved Metals palette.
3. Render a round brilliant diamond using your full 2.5 seven-step technique, sized to sit inside the prongs.
4. Composite: place the diamond layer group so the prongs appear to hold it — a few prong tips should overlap slightly onto the stone's edge for a "gripping" read.
5. Add a soft, subtle cast shadow beneath the whole earring using a low-opacity soft brush on a Multiply layer.