Hand-inked photographs produced by a bichromate process developed by G.E.H. Rawlins ca. 1904. A sheet of paper is coated with a thin layer of gelatin and sensitized with bichromate, dried in the dark and exposed under a negative. Exposure hardens the gelatin in the shadow areas and partially in mid-tones. Soaking in water subsequently removes sensitizer and causes the mid-tone and highlight areas to absorb moisture. Oil based inks are repelled in these areas, and remain to a greater or lesser degree in others. The plate is then allowed to dry or is transfer-printed to another sheet, then re-inked for more prints.
藝術與建築詞典根目錄 
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物件層面
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視覺及語言傳達
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視覺作品 (層級名)
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<視覺作品 (作品)>
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<依媒材或技術區分之視覺作品>
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照片 (視覺作品)
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<依形式區分之照片>
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正片 (照片)
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相片 (正片)
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<依程序區分之攝影相片>
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顏料印相
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油墨印相
[油墨印相 oil prints(編號300138319)]。《藝術與建築索引典》。http://aat.teldap.tw/AATFullDisplay/300138319(2025/04/05瀏覽)。