MATERIAL ATLAS

TPUA flexible material in a printed fidget's base plates

TPU becomes more interesting when you look at where it is used. The 3D-printed RX mini combines TPU base plates, PETG parts and a copper weight within one small fidget.

The yellow-and-black RX mini can look like a single piece of printed plastic. Its published material list tells a more specific story: the base plates, other printed parts and weight use different materials.

TPU stands for thermoplastic polyurethane, a material family available in different formulations and hardnesses. The name helps explain the choice of a flexible component, but does not by itself establish a finished fidget's rebound, friction or service life.

The RX mini 3D-printed edition with its parts overlapping and the lower track visible. The text assigns TPU to the base plates on all six faces; yellow or black alone does not identify a material.

Parts and configuration

RX mini: start with the base plates

An April 2026 product roundup identifies the RX mini as a 3D-printed edition and specifies TPU for its base plates on all six faces. It compares this flexible material to one used in trainers, but supplies no shoe model, material supplier or evidence of an identical grade.

The same passage describes the remaining parts as PETG and separately identifies a pure-copper weight. All three details belong in the configuration: TPU base plates, PETG parts and the copper weight. The phrase about the remaining parts does not turn the explicitly listed weight into plastic.

This is a published product description, rather than a hardness test or a TRB hands-on assessment. The photographs show the printed forms and separated assembly; they do not measure how soft the parts are.

Photographs and figures

Around 35 g belongs to the complete fidget

Separated yellow-and-black RX mini parts on a keyboard, with round inserts visible inside — The same edition with its parts separated. The photograph shows their shape; the published description separately lists PETG and a copper weight without a region-by-region material diagram.

The published figure is around 35 g for the whole RX mini in this configuration, including its weight and other components. It is neither the weight of the TPU base plates nor a specification for every RX edition.

The second photograph separates the yellow-and-black parts, making their outlines and round internal inserts visible. Without an annotated material diagram, colour, an insert or a particular edge cannot be independently assigned to TPU.

For a player, base-plate material, weighting and structure need to be considered together. TPU alone cannot tell you how soft this fidget feels in motion, how much resistance it offers or how loud it sounds. Those questions require testing the actual configuration.

Material background

Flexibility still needs a grade and a hardness

BASF's TPU information presents different formulations and hardness ranges, helping explain why TPU does not have one fixed feel. The RX mini listing provides no Shore hardness, filament grade, printing parameters or cycle-test results.

The listing also makes durability claims without supplying test conditions. This guide retains its material and component details without promising indefinite resistance to ageing or degradation, or applying a material supplier's grade-specific performance to the RX mini.

Useful details to establish for this kind of edition include whether the base plates can be replaced, the hardness and specification of a replacement, and the maker's instructions for that printed part. A similar appearance or the same TPU label does not establish an identical feel.