「柳木之芯」は FontVibe AI で作成した中国墨絵ブラシの文字エフェクトです。中国の墨（すみ）による筆文字書道のスタイルをラテン文字に応用しました。深い黒墨に本物の筆先の質感、太細のはっきりした筆致の変化、そして画仙紙の趣を備えています。中華レストランのブランディング、武術、ウェルネス、文化的なデザインに最適です。

rendered in Chinese ink brush calligraphy style. Letterforms painted with a fully loaded sumi ink brush — deep black ink, visible bristle marks along stroke edges, wet ink pooling at stroke starts, feathered dry-brush trailing ends. Authentic ink density variation: thick rich black cores fading to grey at thin passages. Rice paper texture visible behind. Traditional Chinese calligraphy energy — each stroke confident, intentional, irreversible. LETTERFORM PRIORITY: when the chosen font carries its own treatment, that font's letterform shapes take priority and own the letters; this style governs the sumi ink medium, the bristle and ink-density behavior and the rice-paper ground. FALLBACK MATERIAL: if the font carries no material of its own, render the letters as deep black sumi brush strokes with visible bristle marks, wet ink pooling at stroke starts and feathered dry-brush trails on rice paper. COLOR PRIORITY: keep the font's own colors if specified; otherwise rich black ink fading to grey at thin passages. Create a restrained vertical ink-brush composition on warm ivory xuan paper, with the exact four characters “柳木之芯” arranged in a single descending column, read top to bottom. Give the characters generous breathing room while letting the column command the center of the page. Make 柳 the visual anchor, with 木之芯 slightly smaller but still clear and dignified. Preserve every character accurately and keep the phrase as the only lettering. Let the brushwork feel deliberate and alive: rich black ink gathers at confident stroke starts, thins into smoky grey passages, and breaks into fine bristle trails at the ends. Allow the paper’s long fibers to show through the lighter ink, with subtle feathering where wet strokes meet the ground. Behind the text, suggest the quiet presence of a willow and wood through a few faint ink-wash branches and soft, grain-like washes, kept pale enough never to compete with the characters. Leave broad untouched areas of paper around the column. Add one small vermilion seal impression near the lower corner as a restrained accent, without legible extra text. The finished image should feel intimate, contemplative, and rooted in traditional brushwork.