Oil and bromoil transfer are important variations of the oil and bromoil processes. The process is similar to lithography and is based on the fact that oil and water repel one another.  The oil or bromoil print acts as the printing plate; the ink is transferred from the print to a piece of paper producing an image consisting of ink on paper.

Visually differentiating between an oil transfer and a bromoil transfer can be difficult. The oil process was introduced in 1904 and the bromoil was introduced just a few years later as an improvement to the oil process. Because bromoil prints were made by enlargement, bromoil transfer prints tend to be larger than oil transfer.

There were some slight differences in preparation between a standard oil/bromoil print and one intended for transfer. To make a bromoil print, a silver gelatin bromide print was made by enlargement. The print was treated with a bleaching solution containing potassium dichromate, which hardened the gelatin in proportion to the amount of silver present in the print. Simultaneously the silver was bleached, meaning it was oxidized to its colorless ionic state. The print was fixed and washed resulting in a clear gelatin relief image. The print was then immersed in water and kept damp swelling the unhardened gelatin in the highlights and partially swelling the mid-tones. A greasy lithographic ink was applied to the print with a special brush. The greasy ink was repelled by the water soaked highlights and attached to the hardened shadow areas. The mid-tones absorbed the ink in proportion to the amount of hardening. To prepare a print for transfer, it would be soaked in hot water after printing. This allowed the gelatin to swell more, giving a higher relief and a better printing surface for transfer. However, the print would have less image contrast. Therefore a soft, greasy lithographic ink that transfers well was applied to the print more heavily than usual, especially in the shadows. 

The transfer was originally done in a lithographic press. Presses specially made for the bromoil transfer process were soon available on the market. The inked print was put into contact with a high quality piece of paper, the two were placed between blotters and board, and put through the press. The oil or bromoil print could be re-inked and reprinted on the same transfer print multiple times to build up contrast, or re-inked and printed several more times to make additional prints, allowing for multiple variations of a single image.

An alternate method of printing without a press was to dampen the transfer paper with a solvent like benzene or turpentine so that only light pressure was needed to transfer the pigment from the oil or bromoil print onto paper. 

Oil and bromoil transfer images tend to be soft, making the processes popular with some art  photographers working in the Pictorialist tradition.  Because the final results are pigmented lithographic ink on paper, the prints closely resemble lithographs and can easily be misidentified as such. They were often described or classified in similar ways as pre-photographic prints. One author described the process as being as permanent as an etching with the quality of a mezzotint.