Tubular and reversible double jacquard

Machine types that can knit it

• Single bed (punch card) + ribber
• Single bed (electronic) + ribber
• Double bed with pushers (Passap type)

Steps

1. FNR cast-on, a few circular rows, a few FNR rows, carriage left.
2. Lock the card on row 1, select, knit 1 row right.
3. Main bed: slip both ways (both PART), card unlocked; ribber: slip both ways.
4. Each pass: pull up the ribber needles opposite the gaps in the main-bed selection, following rule A or B consistently.
5. Knit; at the left change colour and re-select by hand; repeat.

The full card

What it looks like

Tubular: face motif, plain back layer, the two layers joined only at the edges (or where colours swap). Reversible/double-face: both faces show the motif with colours exchanged, a "negative" on the back. Diagnostic: the back is a mirror-image colour negative.

How it behaves

Two independent or semi-independent layers. Can be stuffed (tubular). Double-face is thick and stable.

How it works

In reversible DBJ, on each pass the ribber knits the needles opposite the main-bed needles that were *not* selected. Whatever is not knit on the front is knit on the back, so each layer shows the inverse colour. Industrial "full ladder back with 2 colours" is the same idea, called cross-tubular. Tubular uses opposite PART settings, so each bed knits on alternate passes.

Machines

Brother (pre-selecting) + ribber: the ribber needles have to be selected by hand every pass. It works but is very slow; demonstrated only on small samples. Silver Reed cannot do it this way (no preselection). True automation needs selection on both beds (Passap E6000/E8000). Dubied: tubular yes (plain stripes); a reversible picture, no.

Parameters

ribber at H pitch; consistently choose the ribber needle immediately left (or right) of each empty main-bed needle group; 4 passes per 2 design rows.

Steps

1) FNR cast-on, a few circular rows, a few FNR rows, carriage left. 2) Lock the card on row 1, select, knit 1 row right. 3) Main bed: slip both ways (both PART), card unlocked; ribber: slip both ways. 4) Each pass: pull up the ribber needles opposite the gaps in the main-bed selection, following rule A or B consistently. 5) Knit; at the left change colour and re-select by hand; repeat.

Charting

The design chart doubles as both faces. Render the back face as the colour-inverse, mirrored left-right. Pass column with an "RB = complement" note.

Limits and common problems

Selection errors leave holes or double layers. Extremely slow on domestic machines.

Related techniques

• Double-bed jacquard (needs ribber)
• DBJ with bird's-eye backing
• DBJ with striped backing (full and half)
• DBJ with plain (solid) backing
• Ladder backing / Fair Isle tamed by the ribber
• 3–4 colours per row in DBJ