DTF prints have an oil type residue

There are several reasons why your DTF prints may appear 'oily' once cured or pressed on to your fabric. The most common reasons are due to inadequate curing temperatures and/or humidity issues. But why do you see oil residue in the first place?

DTF ink contains glycol. which is used to help prevent the print head from drying up. Glycol is hydroscopic meaning it will absorb moisture. This moisture then becomes trapped between the powder (glue) layer, and if not fully evaporated during curing, the moisture appears on the surface of the print (this can happen immediately or other a period of time).

Some of the solutions are;

Increase your curing temperature and time: Insufficient temperature or curing time can prevent the ink from fully drying, and moisture will remain within the print, leaving an oily residue.

Environment control: Another cause may be high humidity, causing the DTF film to absorb moisture from the environment, leading to uneven ink absorption which in turn effects the curing process.

Controlling the humidity within the environment (lowing the humidity) and keeping the environment consistent will help.
Use a dehumidifier: This can be an effective way of reducing the moisture content within the environment.

Storing film and power correctly: Storing your DTF film and DTF powder within a sealed bag/packaging, even when not it use, will help prevent moisture being attracted to the surface from within the environment.

Use the correct print settings, avoiding laying down too much ink: Too much ink will result in more glycerin which will require increased curing temperature or time to fully evaporate.

Good quality products: The quality of the DTF film and DTF powder will have a direct effect on print output finished quality, including an oil residue appearing on the print surface.

The overall results are effected by several factors such as artwork require different amounts of ink, different ink formulations, different films and the environment. Therefore there is always an element of testing required in each case.