Computer-Aided Textile Design and Digital Tools
What this domain tests
Computer-aided design questions test file setup, repeat building, colour management and the difference between screen and digital output.
Core rules
- Raster images (Photoshop) are pixel-based; vector images (Illustrator, CorelDRAW) are path-based and scale without loss. Use vector for motifs and repeats, raster for textures and photographic effects.
- Resolution: print textiles usually need 200–300 DPI at final size. Pixels = (centimetres ÷ 2.54) × DPI.
- Colour mode: design in RGB for screen, but convert to CMYK or use a printer profile for output; always proof on the actual fabric.
- Repeats: use offset filters or manual tiling; check the seam with a 2 × 2 tile at 100% zoom.
- Colour separation: each screen needs a separate spot colour or channel; digital printing does not need screens but still needs correct colour profiling.
- Useful tools: NedGraphics, Pointcarre, ScotWeave and Arahne for woven or knit simulation; Photoshop actions for repeat; Illustrator pattern tool.
Worked example
A 40 cm repeat is to be printed at 300 DPI. Convert: 40 ÷ 2.54 = 15.75 in; 15.75 × 300 = 4724 px. Set the canvas to 4724 × 4724 px at 300 DPI. If the design has six colours, prepare six spot channels for screen printing, or one CMYK file for digital printing. Reasoning: sizing in pixels prevents resampling; spot channels keep each colour pure; a CMYK conversion may shift a bright orange, so proof it.
Traps
Designing at 72 DPI for print; building a repeat on a canvas that is not an exact multiple of the motif; forgetting to embed fonts or link images; using RGB black for a deep print black; flattening layers before colour separation.