中原慎一郎決定以玻璃作為物料，於是請來了Craft U合作。Craft U的社長由1965年開始便入職玻璃製作公司，經驗老到的他擅長用Burner Work來生產玻璃。一般的口吹玻璃形狀較難控制，倒模的話，形態則太過規規矩矩，而Burner Work是邊用火槍以二千度高溫燒熔玻璃，邊利用轉盤為玻璃造形，因此能夠造出精細且富人情味的製品。
Watching the water slowly dripping down, observing how the amount of water decreases on the top part and slowly fills up the lower container — the water filter jug indeed resembles an hourglass, with its steady water dripping sound marking the passing of time.
The famous Japanese designer Shinichiro Nakahara is the project director behind this water filter jug by Cleansui, with the manufacturing process taking place in a small glass factory in Niigata Prefecture called Craft U. This is not the first time Nakahara collaborated with Cleansui; the two have previously teamed up to create a ceramic filtered water dispenser. Nakahara even visited Shigaraki, home to the production of Shigaraki Ware, to invite artisans to join the production team. The filtered water dispenser is very heavy in weight so it can only be stationed at a certain spot at home. When being invited by Cleansui for the second collaboration, Nakahara wanted to create a handy jug. Instead of a water dispenser that constantly supplies people with filtered water, he would like to create something that is to be used in particular moments. If you are exhausted from work, or when you want to brew some tea when friends are visiting, the beautiful water jug can always make the moments even more enjoyable.
After deciding to pick glass as the material, Nakahara invited Craft U to join the team. The director of Craft U began his career in the glass manufacturing industry in 1965. As an experienced glassmaker, he is skilled in flameworking. While it is difficult to control the shape of the end-product when using the glassblowing technique, glass casting creates shapes that are too conventional. Flameworking is a process that uses a torch over two thousand degree celsius to melt the glass while shaping it with the help of a lathe. This process can create shapes that are delicate with a nice human touch.
Among the numerous crafts in Japan, many of them were in fact rather unnoticed. To show to the public a more concrete picture of these crafts, Cleansui would upload videos of the production process to their website, hoping to bring people closer to the essence of the crafts.