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Flag of Koshigaya Saitama Japan - Color Changing Mug 11oz

Flag of Koshigaya Saitama Japan - Color Changing Mug 11oz

100 in stock

Regular price $17.99 USD
Regular price Sale price $17.99 USD
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Flag of Koshigaya, Saitama - Color Morphing Mug Design

This design reproduces the flag of Koshigaya, a city in Saitama Prefecture, just north of Tokyo, as a single, self-contained civic emblem.

Visual Elements & Composition

A municipal flag works through economy. Its colours, shapes and central device are arranged to be read at a glance from a distance, with nothing decorative added around them. Here the flag is rendered in full colour across the whole wrap, so the emblem sits centred and unbroken, with its edges running cleanly around the curve of the cup. Every mark is deliberate, and the composition gives the eye one clear focal point rather than competing details.

Meaning & Symbolism

A city flag is a compact statement of identity. Its symbols are chosen by a community to stand for its place, its history and what its residents want to be known for. Koshigaya is a long-established city in the Kantō region, and its flag carries that sense of local belonging into a form people can recognise instantly. Flags like this are often adopted to mark civic pride, so the design reads as a badge of place rather than a picture of a single moment.

Made for the Hand and the Morning Cup

A mug is held, turned and looked at from close range, and this flag is built for exactly that. The emblem is drawn to be seen as you rotate the cup, and the hot-drink reveal gives the design a second life: the flag appears as the cup warms, then fades back as it cools. That slow transformation suits a flag, which is meant to be noticed, not just displayed. It makes a thoughtful gift for someone with roots in Koshigaya, or for anyone who likes a design with a story behind it.

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Color-changing ceramic mugs with a glossy finish, black exterior, and white interior. Available in one size: 11 oz (≈330 ml). Heat-reactive coating reveals your custom design when filled with hot liquid. BPA- and lead-free, with a comfortable C-handle.

This mug brings a playful twist to the daily coffee or tea ritual. At room temperature, it looks like a simple black mug with a glossy finish. But add a hot beverage, and your chosen design fades into view, showing vivid colors against the white interior.

The ceramic body is durable enough for repeated use, while the C-shaped handle balances comfort and grip. Printing uses sublimation techniques that fuse color into the heat-reactive surface for crisp results when the design appears.

  • Material: ceramic with glossy black exterior and white interior.
  • Size: one standard size, 11 oz (≈330 ml).
  • Finish: glossy glaze with heat-sensitive surface.
  • Printing: sublimation process produces crisp, vibrant colors.
  • Safety: BPA-free and lead-free, suitable for everyday drinks.
  • Effect: design is faintly visible when cold, fully revealed when hot.

Perfect as a novelty gift or a fun personal mug, the heat-reactive design makes coffee breaks more engaging. It works well for morning coffee, afternoon tea, or hot chocolate.

  1. Daily routine: fill with any hot beverage to reveal your chosen artwork.
  2. Gifting: the “magic” reveal makes it a memorable present for birthdays, holidays, or office exchanges.
  3. Office use: sparks conversation while still being practical for everyday drinks.

Note: for best results, avoid designs that rely heavily on deep black backgrounds, as they may blend with the mug’s surface when cold.

Unlike standard mugs, color-changing mugs require gentler care to preserve the heat-reactive coating. Hand-wash only — avoid the dishwasher and abrasive scrubbers, which can damage the finish and reduce the effect.

The mug is safe for short microwave use when heating liquids, but repeated high-heat cycles may shorten the lifespan of the coating. Always allow the mug to cool before washing.

Available in one classic size: 11 oz (approximately 330 ml). It’s large enough for most standard coffee makers and fits comfortably in most cabinets.

Size guide

All measurements are product dimensions in inches.

11 oz
Height (in) 3.78
Diameter (in) 3.23
Diameter w/ handle (in) 4.76

Note: measurements are approximate; slight variations may occur due to manufacturing tolerances.