►Core parameters and functions
Inner diameter: determines bristle fluffiness and powder collection area.
Length : affects bristles support and elasticity .
Shape: round, angled, special-shaped mouth, corresponding to different brush types.
Length : affects bristles support and elasticity .
Shape: round, angled, special-shaped mouth, corresponding to different brush types.
►Ferrule sizes and brush types
| Inner Diameter（mm） | length（mm） | Applicable brush type | Features | Representative Products |
| 3-5mm | 8-12mm | Detail Eyeliner Brush | Tight and dense brush head, precise lines | MAC 210S |
| 6-8mm | 10-15mm | Pencil brush | Small area coloring, suitable for triangle area at the end of the eye | Hakuhodo B005G |
| 9-12mm | 15-20mm | Medium Eyeshadow Brush | Evenly take powder and quickly apply base | Sigma E25 |
| 13-18mm | 20-25mm | Stippling blush brush | Loose brush head, natural smudge | Qingzhi G081 |
| 19-25mm | 25-30mm | Tongue shape foundation brush | High-density bristles, polished without marks | Artis Oval 7 |
| 26-35mm | 30-40mm | Round powder brush | Fluffy powder, full face makeup | Chikuhodo Z-9 |
| Angled/special shape | 15-25mm | Fan brush, nose shadow brush | Fits facial contours for precise contouring | Sonia G. Sculpt Three |
►Key parameters and selection guideline
1. Inner diameter determines function
＜5mm：Ultra-slim, suitable for precise lines (such as eyeliner and concealer).
6-12mm：Universal eyeshadow brush range, choose tightness as needed (the larger the inner diameter, the fluffier)
＞25mm：Large powder brushes need long ferrules (30mm+) to improve the bristle elasticity.
6-12mm：Universal eyeshadow brush range, choose tightness as needed (the larger the inner diameter, the fluffier)
＞25mm：Large powder brushes need long ferrules (30mm+) to improve the bristle elasticity.
2. The ferrule length affects the support force
Short (＜15mm)：Stiff bristle, suitable for cream products (such as concealer brushes)
Long(＞25mm)： Soft bristles, suitable for powder blending (like a blush brush).
Long(＞25mm)： Soft bristles, suitable for powder blending (like a blush brush).
3. Shape and brush type
Round: basic all-purpose (such as loose powder brush, eye shadow brush).
Angled: fits the curve of the face (such as angled contouring brush).
Flat: precisely controls the range (such as tongue-shaped foundation brush).
Angled: fits the curve of the face (such as angled contouring brush).
Flat: precisely controls the range (such as tongue-shaped foundation brush).
►Process and Pitfall
Stamping:
Integrated stamping ferrule (no welding seam) is more durable, representative brands: Hakuhodo, Chikuhodo .
Low-priced brushes often have welded ferrule, easy to crack and hair loss
Copper ferrule vs. aluminum ferrule:
Low-priced brushes often have welded ferrule, easy to crack and hair loss
Copper: high cost, strong corrosion resistance (preferred by professional brushes, such as Wayne Goss).
Aluminum: lightweight, suitable for portable brushes (such as Real Techniques).
Aluminum: lightweight, suitable for portable brushes (such as Real Techniques).
Hair bundle fixing:
Epoxy resin glue: environmentally friendly, but poor water resistance (avoid frequent soaking and cleaning).
Metal rivets: high-cost, representing top-level handmade brushes (such as Smith Cosmetics).
Metal rivets: high-cost, representing top-level handmade brushes (such as Smith Cosmetics).
►Typical products
| Brush Type | Ferrule inner diameter | Ferrule length | Material/Craftsmanship | Brand Model |
| Detail Eyeliner Brush | 4mm | 10mm | Copper ferrule + epoxy resin glue | Hakuhodo B531 |
| Blending brush | 10mm | 18mm | Aluminum one-piece stamping | Sigma E40 |
| Stippling blush brush | 15mm | 22mm | Copper ferrule+ metal rivet fixing | Chikuhodo Z-4 |
| Flat foundation brush | 22mm | 28mm | Aluminum ferrule welding + antibacterial coating | Morphe M439 |
►Golden rules for purchasing
Eyeshadow brush: inner diameter 8-12mm + 15-20mm length to balance powder collection and blending.
Powder brush: inner diameter ≥25mm + ≥30mm length to ensure fluffiness.
Pitfalls：
Unbalanced ratio of inner diameter to length (e.g., a 20mm inner diameter with a 15mm short ferrule, easily lead to bristle loose).
The welding burrs can easily scratch skin (check the smoothness when purchasing).
Powder brush: inner diameter ≥25mm + ≥30mm length to ensure fluffiness.
Pitfalls：
Unbalanced ratio of inner diameter to length (e.g., a 20mm inner diameter with a 15mm short ferrule, easily lead to bristle loose).
The welding burrs can easily scratch skin (check the smoothness when purchasing).
Summary:
The ferrule size is the "invisible skeleton" of the brush function. Only by matching the parameters as needed can you unlock professional-level makeup effects!
