The pattern for the bas relief (raised) pink heart in the photo above comes from the book Pin Loom Weaving by Margaret Stump so I haven’t included it herein.
But I invented the pattern for the sunken heart depicted in the other squares, so I’m sharing it here.
The method I use is: Warp the first three layers in one color, then switch to a second color for the last layer. I wrap an extra five wraps around the loom–9 3/4 wraps total–and either tie on at the end of the long strand and weave pulling the extra long length through, or tie on after the 5 wraps. When finished I either crochet the border from corner four or two. Weaving the entire length puts the crochet tail at corner four. It doesn’t matter which way you choose; it just depends on where you want your final knot or whether or not you mind pulling an extra long weaving length through your work.
Please keep in mind these instructions are the intellectual property of Sue Burton. Do not copy or sell them. You may share the link to this blog.
Row 1: Plain weave (P)
Row 2: U-3, O-1 across; end with U-3
Row 3: P-2; U-3, O-1 (2x); U-3; P-5; U-3, O-1 (2x); U-3; P-2
Row 4: U-3, O-1 (2x); U-3; P-9; U-3, O-1 (2x); U-3
Row 5: P2; U-3, O-1, U-3; P-13; U-3, O-1, U-3; P-2
Row 6: U-3, O-1, U-3; P-17; U-3, O-1, U-3
Row 7: P-2; U-3; P-21; U-3; P-2
Row 8: U-3; P-25; U-3
Row 9: P
Row 10: Repeat row 8 [Or see Variation instructions below]
Row 11: P
Row 12: Repeat row 8
Row 13: P-2; U-3; P-9; U-3; P-9; U-3; P-2
Row 14: U-3, O-1, U-3; P-5; U-3, O-1, U-3; P-5; U-3, O-1, U-3
Row 15: P-2; U-3, O-1 across; end with U-3; P-2
Row 16: P
Variation for Row 10: P
[This will produce the effect in the pink/blue heart shown in the photo.]
As you can see in the photos below, the effect of the raised heart on its reverse side is different while the sunken heart itself looks the same on both sides.
The heart is less obvious in this two-color version. Layers 1 and three in green; layers 2 and 4 in pink.