Convert JPG to PAT

A graphics program may require a PAT file when a JPG must become a reusable texture, fill, or tiled background instead of remaining a standalone image. The correct conversion depends on whether the destination is GIMP or Adobe Photoshop, because their PAT files and preset workflows are not fully interchangeable.

What the JPG format is

JPG, also called JPEG, is a lossy raster-image format used by cameras, phones, scanners, web browsers, and image editors including Photoshop, GIMP, Affinity Photo, and Paint.NET. It stores pixels efficiently by discarding image information, which makes it suitable for photographs but can reduce quality after repeated editing and saving. JPG files commonly use RGB or grayscale color, although JPEG also supports other color models. A JPG contains ordinary image pixels, not pattern metadata.

What the PAT format is

PAT is used by several graphics applications for patterns that repeat across a larger area. Photoshop uses PAT files for pattern presets used by fills, brushes, layer styles, and related tools; GIMP uses PAT files for image patterns. A pattern can turn a small texture, fabric sample, wallpaper design, or other tile into a repeating surface.

There is no single universally interchangeable PAT specification. A GIMP PAT file and an Adobe Photoshop pattern preset can use different structures, and a file accepted by one application may be rejected by another. Select the destination program before exporting. PAT also does not automatically make an image seamless: mismatched edges remain visible at every tile boundary.

How to convert a JPG to PAT

Using GIMP

1. Open the JPG with File → Open.
2. Crop or resize the image if the pattern requires a specific tile size. Use Image → Mode to select RGB or grayscale when the destination requires a particular color mode.
3. Check the edges at the intended repeat points. Use Filters → Map → Tile Seamless where available, or repair seams manually with GIMP's clone, heal, and paint tools.
4. Choose File → Export As, enter a filename ending in .pat, and select Export.
5. Enter a pattern description in GIMP's PAT export dialog and confirm the export.
6. Place the file in GIMP's patterns folder if it does not appear automatically, then refresh the Patterns dock or restart GIMP. The folder location varies by operating system and GIMP version.

GIMP is the most direct free desktop option when the target is a GIMP-compatible PAT file.

Using Adobe Photoshop

1. Open the JPG with File → Open and prepare the image as a tile. Correct seams and set the required dimensions before defining the pattern.
2. Select the entire canvas or the area to use, then choose Edit → Define Pattern.
3. Enter a name and select OK. Photoshop adds the pattern to its current pattern library.
4. To create a distributable PAT preset, open Edit → Presets → Preset Manager, set the preset type to Patterns, select the pattern, choose Save Set, and save the set with a .pat extension. Menu names can vary between Photoshop releases.
5. Load the preset later from Photoshop's Patterns panel or its pattern import command.

Photoshop is the safer choice when the PAT file must be used as an Adobe pattern preset. Defining the pattern directly in Photoshop avoids relying on cross-application PAT compatibility.

Using an online converter

Convertio is a reputable online option for non-sensitive images, but use it only when its current format selector explicitly lists PAT as the output format. Online services may produce a GIMP PAT file, an Adobe-compatible preset, or a file that the intended application cannot read; verify the output in the target program. Do not upload confidential, copyrighted, or unpublished images unless the service's storage and deletion terms are acceptable. For predictable PAT structure, use GIMP or Photoshop locally instead.

Quality and compatibility limits

Conversion cannot restore detail removed by JPEG compression. Start with the highest-quality original, avoid enlarging the JPG, and save an edited master as PNG or TIFF before exporting PAT. PNG or TIFF preserves a cleaner source for later revisions, although the final PAT may still use the format and color limits imposed by the destination application.

Tile dimensions affect both appearance and resource use. Small tiles repeat frequently and make seams or motifs obvious; large photographic tiles consume more memory and can slow pattern previews. Resize and crop before export rather than relying on the pattern tool to correct unsuitable dimensions.

Test the file in the exact application and version that will use it. If Photoshop rejects a GIMP-generated PAT file, define the pattern in Photoshop and save it through Photoshop's preset tools. If GIMP does not recognize an Adobe PAT preset, export the prepared image as PNG and create a new PAT file in GIMP.