It may be one of the least known aspects of furniture, and of other objects too. It is material(s) and the work which aims to shape and define the expression of the base material to the outside world. In its most functional sense, finish acts as a protective shield for the material underneath, guarding it against damage from physical or other environmental elements like water or dirt. As the finish material itself has its own characteristics, when applied, it shapes the color, depth, sheen, and even touch of the base material, defining the overall character of the object.
A refined finish effect for solid wood furniture should be lively, highly transparent, thin but thorough, and full of character. Unless for opaque effect, it should allow the wood grains to be clearly seen even in a dark color. It should be fresh and smooth to the touch. For the finest finish one may even be tempted to gently stroke and enjoy the silky smoothness with the hands. Purely handmade, it should exude a warmth absent in industrialised methods of finishing.
The choice of a finish calls for deep understanding of both the finish and the base material. On top of aesthetics considerations, how do they respond to each other? Is the protection expected fulfilled? Is there any odour or harmful emission? Is there sufficient skill to perform? Is it long lasting? Does it age well and grow into a patina? Is there enough crafting time allowed? Is future restoration possible? It is therefore as much a technical consideration as an aesthetics consideration.
Those who have knowledge on make-up know that no make-up can be pleasing unless the skin foundation is properly prepared. This is also true for furniture finishing. In fact the time and skill required to develop a sound foundation should surpass that for the final finish material at the top. When one appreciates a fine finish, most of the credit should go to the crafting effort in the foundation. Therefore, when viewing the list of finish materials below, one should never forget the unsung hero behind. The finish materials are also not used exclusively, these are quite likely used in different cycles of the finishing process for the best overall effect. And these are used for our solid wood clear finish furniture, other finishes such as spray paint piano finish are not covered here.
Called urushi（うるし）in Japan and qi（漆）in China, it is a natural resin extracted from the sap of a tree called lacquer tree (genus rhus verniciflua) indigenous in south east Asia, found at altitudes between 3,000 to 7,500 feet. The sap is usually gathered when the trees are 10 to 15 years of age, and the trunk at least 10cm in diameter. From June to October, the collector makes parallel cuts in the trunk with a knife. Then the sap, a thick milky-white liquid oozing naturally out of the tree, is scraped off with a spatula and collected.
After the lacquer is extracted in a year, the tree is left to recover for five to seven years before the next extraction. The most a single tree can yield is 50 grams of lacquer, hence its preciousness. After filtering impurities and slowly reducing its water content, the lacquer is ready for use. In its liquid form, the lacquer is highly irritant, but once hardened most people won’t show any allergic reaction.
Natural Lacquer is extremely durable, being able to stand for generations without cracking or chipping. It is very resistant to strong acids and alkalis. It also is water resistant, and heat resistant to 230 degrees Celsius. The only caution is a lacquered object shouldn't receive too much sunlight, because ultra violet light will decompose its molecules.
One major difference of Natural Lacquer from most other types of traditional finish is that it is cured by non-reversible chemical polymerization reaction, not by the evaporation of a solvent. The curing process is also contrary to common knowledge, it cures in a humid and warm room, air-drying is difficult if not outright impossible in most climates. Being 100% natural, it also doesn’t release harmful odour to harm your health.
A Natural Lacquer finish is said to have a life because even after completion, its transparent finish will grow even more crystal clear over time, when more oxygen is absorbed into the finish from the air – which makes the finish even harder. This is different from most other finish, which turns yellow or cloudy when the finish ages.
Japan is laudable with its effort to keep alive the noble tradition of the art of Natural Lacquer, much more so than China. However, most of what they do only apply to small household if not decorative objects. They also tend to use opaque and coloured lacquer rather than keeping the original transparency of the Natural Lacquer. The base material can be soft wood, bamboo, and even orange peel!
In mastering Natural Lacquer on hard wood in a massive scale, we are probably quite unique in the whole world.
Please view below a series of photos showing how the Natural Lacquer progresses from its source all the way to a fine finish.
漆，英文 Natural Lacquer, 日文 うるし (Urushi), 是一种天然树脂，从漆树树皮下收采的汁液提炼而成。漆树学名为 rhus verniciflua, 普遍生长在东南亚三千至七千五百尺的山上。当树龄大概十到十五年，而树干直径最少十公分，树皮汁液就开始给开采。每年从六月至十月，开采者就会徒手爬上漆树，在树皮上刻刮出一条一条的平衡沟槽，溢出的白色汁液就会被一个特制的金属刀收集。
用漆来处理的器具异常耐久，可以世代使用而不会爆裂或崩开。漆也对酸碱等的化学物质有抵抗性，并且防水，还能抵受至 230 摄氏度的高温。唯一弱点是漆不可长时间受日晒，因为紫外光会破坏漆的分子。
日本在延续漆器这高尚工艺方面比中国造得更好。但他们主要只是将漆应用在小器皿或装饰物件上。同时大部分的涂漆效果都是不透明的黑漆或红漆，厚厚的一层遮盖着底下的物料 - 包括软木，竹，甚至是橙皮！
It is a light yellow or orange colored animal resin, the secretion of the lac beetle found on trees in India and Thailand. It is dissolved in alcohol, and dries to form a clear and durable finish, though slightly yellowish. Its use is most well known in the French polish, where the surface is repeatedly buffed to yield a high gloss effect. It is a key finish material used to make fine furniture in the west over the past couple of centuries, with the process called Japanning because it is used to mimic the result of Natural Lacquer.
Different from Natural Lacquer it dries by the evaporation of the solvent material. This property causes the finish to be reversible, in other words solvent can be lethal to a finished piece of furniture because its subsequent application can ruin the fine finish, but at the same time the finish can be repaired with relative ease.
虫胶的行内名称为士力，是一种黄色至橘色的动物胶脂，从一种遍布于泰国印度等地称为 lac 的小虫所分泌的物质。用酒精溶解后就可使用，在家具表面固化后就变成透明而耐用的涂层，尽管轻微泛黄。它最有名气的使用场合是用在“法国涂漆”上，公丈会不断用沾有士力溶液的棉球在家具表面不停摩擦，让涂漆表面闪闪生光。它是西方过去几百年重要的家具涂漆物料。其涂漆过程也被称为“仿日本”，因为士力的涂漆光泽如果技巧优良的话跟漆有点相近，而当时西方人认为日本就是漆的发源地。
wax / wax oil
It is used either in its own right, or as a final protection to other finish materials. Depending on the application requirement, we may use pure beeswax, which is the natural wax secreted by young bees; or wax oil, which is a pre-combined mix of plant based oil and wax. On top of further shielding the wood from environmental humidity change, it also adds to the surface smoothness and lustre.
Of all the three finish materials covered, wax / wax oil usually yields the most natural finish, that is enabling the original character of the timber to be displayed in its full. It is also the easiest to maintain over time. However, it won't achieve the elegant lustre of shellac, let alone Natural Lacquer.