Before You Buy – Body Imperfections

The Smart Doll body is made of sofubi (soft vinyl) using a technique known as slush casting—a process similar to handcrafted pottery, where each piece carries its own unique surface details.

Unlike mass-produced components, slush casting is a multi-step, hands-on process. Vinyl is poured into electroplated molds, which are then placed into air chambers and centrifugal units to reduce bubbles. The parts are baked in a temperature-controlled oil bath using a non-boiling thermal oil called Torec, then carefully removed once cured.
Each stage of this process leaves its mark—whether it’s flow lines, tiny dents, bumps, air bubbles, or asymmetry. Even the molds themselves contribute to these characteristics, as they inherit surface textures that are transferred to each part.

These signs of craftsmanship may come as a surprise to those more familiar with the polished perfection of factory-mass-produced goods. That’s why we’re sharing this—so you know what to expect before you make a decision.
We understand that not everyone appreciates these natural inconsistencies—and that’s completely okay. But for those who find beauty in handcrafted work, we hope this helps you see why we consider each Smart Doll perfectly imperfect.

All vinyl body parts are naturally asymmetrical in both shape and thickness due to the hand-casting process. Surface characteristics may include dents, bumps (image 1), flow lines (image 2), air bubbles (image 3), or birthmarks (image 4). Internally, parts may contain solidified vinyl drips, which are a typical byproduct of slush casting (image 5). These features are expected in handcrafted vinyl products and are not considered defects.

As shown in image 4, every Smart Doll includes a support socket located on the back. This socket is designed for attaching support stands and compatible accessories to assist with display and posing. While it’s not a common feature on most dolls, some folks have shared that they weren’t aware it was there—so we wanted to point it out here just in case.

We’ve also received requests to produce Smart Dolls without the support socket. However, the socket isn’t just for holding the stand—it also plays an important structural role in the assembly of the body. Without it, the doll cannot be properly constructed.

All Smart Dolls shipped after March 2023 feature the latest-generation skeletal frame, known as Evolve (image 7). One of the most significant upgrades is the geared joint design, which improves durability, enables smoother movement, and offers a more lifelike posing experience. The joints now provide both tactile and auditory feedback—a distinct clicking sound that some may find loud (image 8). While this adds a satisfying sense of control during posing, it may come as a surprise to those new to Smart Doll—so it’s something to be aware of before making a purchase.

Limbs are not physically attached to the internal frame but are instead wrapped around it. Because each part is individually cast with slight variations in wall thickness, some wiggle may be noticeable when handling. This is especially true for larger parts, so limbs on Pear and Guy bodies may feel looser in the hand compared to those on the Classic body.

While the internal frame components are injection molded to ensure the precision needed for articulation, each frame is assembled and hand-tuned to fit the unique shape of its corresponding vinyl body. As a result, joint stiffness, as well as the haptic and auditory feedback, will vary from one Smart Doll to another.

The unique asymmetrical design of Smart Doll also extends to the limbs, resulting in subtle variations in the shape and length of arms and legs (image 9). This is not a deliberate design decision to make one limb longer than the other, but rather a natural result of the casting process, where each part forms with its own character.

Smart Dolls can stand upright when the legs are positioned slightly apart and the hips are adjusted correctly. With proper stance and alignment, the doll can maintain a balanced and stable pose.

The head cap may not appear to fit perfectly, as each head is individually cast with differences in mold and wall thickness. It may look visibly larger or smaller than the head itself, but this does not affect its core function of securing a wig in place (image 6).

All head caps—regardless of the Smart Doll’s skin tone—are produced in a distinctive cybernetic orange (image 6).

Similarly, subtle differences in skin tone may be visible between body parts, as each piece is individually cast.

The longevity of color in sofubi can be influenced by environmental conditions. UV exposure, heat, humidity, oxygen, and airborne pollutants can all contribute to changes in appearance over time. Lighter tones—especially white and pale colors—are more prone to visible yellowing, which may occur more quickly than in darker shades. This is a common characteristic of vinyl materials and is primarily the result of natural processes such as oxidation and photodegradation.

Fabrics that come into contact with the Smart Doll vinyl body may cause discoloration over time. This can happen not only with dark or highly pigmented fabrics, but even with white or light-colored ones—particularly if they retain moisture, trap odors, or absorb pollutants from the environment. These conditions may accelerate polymer degradation or cause chemical migration, leading to staining or other surface changes.

Please note that discoloration—whether caused by third-party clothing or our own apparel—is not covered under warranty, as it results from environmental and material interactions beyond our control.