[ 彩材拆拆 x UNWRAP CMF ]
Ch14. Unwrapping CMF Design on Unavoidable Color Differences
Ch14. 拆招CMF設計談難以避免的色差
CMF is a specialized area within industrial design that focuses on the development of products‘ color, material, and finish. Unwrap CMF shares bite-sized stories with digestible contents for anyone and everyone, inspiring curious minds about CMF Design. Enjoy learning? Use the mentioned terminologies to kick-start your research journey. Messages are always welcome! LinkedIn | Instagram | Email ✉️
Last chapter briefly introduced CMF sign-off, where designers decide an acceptable limit range from production. Sounds simple, right? (中文請見下方)
Let’s start with a little experiment: go look for items with black matte finishing, such as a laptop or water bottle cap. Next, drop a bit of water on the surface to simulate partial gloss. Compared to glossy black, doesn’t matte black always look somewhat “gray-ish” and no way to look as black as the glossy black?
That says, even with the same material and process, colors can vary across different finishings. Glossy surface treatment usually makes color appear darker and more saturated.
Color stability also differs across materials and processes. For example, coloring of metal-like pearl painting is relatively stable once the recipe is fixed. In contrast, coloring of anodized metal is more challenging. Staying just 0.01 second longer or placed in different locations in the anodizing sink can already cause color difference within the same batch.
Some materials and processes also come with coloring limitations, such as PVD process can achieve yellow and blue, but cannot achieve red and purple without hiccups.
Rumor says that Apple owns color-sorting assembly lines that can divide color limits into groups, and then assemble different parts of the same color together. That explains why color difference is rare on iPhone, but everyone’s rose gold iPhone can look different. In any case, this color-sorting assembly line requires high investment and strict SOP, and is not a model that any other company can easily adapt to.
The challenges of CMF sign-off process is not only to determine an acceptable color range, but also to consider the various materials and processes used on the product, as well as their respective color stability and limitation. And don’t forget, the narrower the limit range, the higher the production cost. It really is not that simple.
CMF全稱為Color Material and Finishing,屬於工業設計旗下專注於產品色彩、材質、及表面處理工藝的關鍵一環。UNWRAP CMF 彩材拆拆圍繞著這個主題,以淺而易懂的小故事拆解CMF設計的日常。CMF學無止盡,善用CMF關鍵字繼續網上鑽研。討論交流請來信至 LinkedIn | Instagram | Email ✉️
上一篇簡單的介紹了CMF簽樣,也就是在試產的樣品中,由設計師定奪一個可接受的顏色範圍。聽起來是不是很簡單?
先做個小試驗:轉頭找找黑色霧面的物品,比如筆電外殼、寶特瓶蓋等。接下來,在表面上滴幾滴水用來模擬局部高光。有沒有發現,相對於高光黑,霧面黑總是灰濛濛的,沒有辦法做到高光黑的「極黑」。
由此得知,即使運用同款材質及工藝,不同光啞所呈現的色彩也各自有異。高光的表面處理會使色彩顯得更深也更為鮮豔。
各種材質及工藝的顏色可控程度也是大相徑庭。比如仿金屬的珠光噴塗在確認配方比例之後,批次之間的色彩及光澤會相對穩定。相比之下,陽極噴砂金屬就較具挑戰,哪怕是在陽極槽內多滯留0.01秒,或置於槽內不同位置,都恐怕造成色差,因此批次與批次之間、甚至同個批次的樣品都可能帶有色差。
除了色彩穩定性,有些材質及工藝亦帶有色彩侷限,比如運用靶材著色的PVD鍍膜工藝能輕易做到金黃色系及藍色系,但紅、紫色系都相對困難。
據說蘋果有一套能辨色分類的組裝線將不同的顏色限度分為批次(俗稱月老機),再將同色的不同配件組裝,所以同產品上的不同配件能輕鬆做到同色。這也說明了為什麼iPhone本身鮮少色差,但不同人的玫瑰金iPhone卻能天差地遠,以及分開販售的配件(如錶帶)的色差機率較高。無論如何,辨色組裝線是極高的投資及嚴格的標準作業程序,恐怕不是其他公司能輕易效仿的模式。
CMF簽樣的難題不僅僅是判定一個可接受的顏色範圍,而是需要多方面的考量產品上所運用的各種材質與工藝,以及它們各自的色彩穩定性及工藝侷限。何況別忘了,限度範圍愈窄,生產成本就愈高,所以真的沒那麼簡單。


Color-sorting assembly line can put same-color parts together, but separately sold parts (i.e. watch strap) cannot be sorted like this.

Color stability varies across processes and materials, such as painted plastic and anodized metal, hence the color difference.

Different reflection across various materials can also cause color gaps, as one of the challenges in color-matching.