use this technique in order to emphasize the contour of the object. To do it you have to entwine two warp threads (front and back) with the working thread. To make a contour we usually use thicker threads.
Weaving techniques that might be helpful (not for card weaving but for weaving where the warp threads are spaced further apart. This board is very useful for details about weaving. (For stories about Peruvian children and adults weaving
Rebecca Mezoff, Tapestry Artist: Weft tension: how to control the amount of weft used in tapestry weaving. This is an example of a section of warps coming together drastically. More weft is needed to correct this (or prevent it!
Chrissie Freeth - woven on a traditional upright loom. "My work is usually large scale and take months to weave. I use hand-dyed wool and a palette heavily influenced by the muted colours of the Yorkshire landscape.