Samsung Electronics' foldable phone prototype appeared at CES 2019, although behind closed doors, as the company showed it to customers only.

The highly-anticipated device brefly appeared last month at the 2018 Samsung Developer Conference and according to Samsung executives, the electronics maker is currently finishing up optimization processes for its foldable phone’s hardware and software.

When unfolded, the foldable device does not show any crease indicating it had been bent, offering an edge-to-edge a smooth screen experience. But
completely folding the device will lead to a breakage. For this reason, Samsung is testing out the device so that the sides remain slightly lifted when folded. The current prototype leaves a crease mark when being folded, but this issue is expected to be fixed in the finalized version. The large display of the phone is designed to offer space for multitasking -- for work but also entertainment.

Samsung plans to launch its foldable phone in the first half of the year, but the number of devices that will be produced is expected to be significantly smaller than the typical production quota set for Samsung’s flagship Galaxy S series smartphones. The price of the new premium device is expected to be not less than $1,300, as it packs the latest flexible display and battery technology.

Also at CES, Chinese technology company Royole showcased the world’s first commercialized foldable phone with a flexible display: the Royole FlexPai.

When unfolded, the FlexPai looks more like a small tablet PC than a smartphone, due to its wide screen. It also feels thicker overall than a standard flagship smartphone, and becomes even bulkier when folded.

As for its design, the phone did not leave any creases when folded or unfolded. Royole says that durability tests have proven that the phone can be folded more than 200,000 times before breakage issues emerge.

When folded, the phone takes on three different screens -- one side, the opposite side and the middle crease section. On the home screen, one main screen brings together all the apps, after which the phone can be used more like a standard smartphone.

The FlexPai is already available for purchase in China at between $1,318 and $1,469. It will be rolled out in global markets in the following months.