purlJam

# Geometric Mosaic Blanket
### An Advanced Overlay Mosaic Crochet Throw (UK terminology)

A bold, reversible-look mosaic blanket worked in two contrasting colours. Using the inset mosaic method, you work one colour per row and create crisp diamond-and-cross motifs by working **tr** down over earlier rows. The result is a dense, warm, graphic throw — perfect for confident crocheters ready to read a chart.

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## FINISHED SIZE
- **Width:** approx. 132 cm (52 in)
- **Length:** approx. 152 cm (60 in)
- Including border: approx. 138 × 158 cm

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## MATERIALS
- **Worsted (Aran-lite) weight yarn**, smooth plied for stitch definition:
  - **Colour A (dark):** approx. 900 m (≈ 4–5 × 100 g balls)
  - **Colour B (light):** approx. 900 m (≈ 4–5 × 100 g balls)
  - Total: approx. 1700–1800 m
- **Hook:** 5.0 mm (H/8) — *use 5.5 mm (I/9) if you crochet tightly*
- Yarn needle (for weaving in ends)
- 4–6 locking stitch markers
- Tape measure

> **Yarn note:** Choose two solid colours with strong contrast. High contrast makes mosaic motifs pop; low contrast hides them.

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## TENSION (GAUGE)
- **15 dc and 17 rows = 10 cm (4 in)** in mosaic pattern on 5.0 mm hook.
- Work a **6 × 6 inch (15 cm) swatch** in the mosaic pattern (chart below), then block before measuring.
- *Float check:* Carry floats loosely. If the swatch puckers, your floats are too tight; if loops sag, too loose.

**Tension validation:** 199 working sts ÷ 15 sts per 10 cm × 10 = **132.7 cm width** ✓

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## LAYOUT & TECHNIQUE — Allover Inset Mosaic
This blanket uses a single allover mosaic chart repeated across the width and up the length.

**Key principles of inset (overlay) mosaic:**
1. You work **one colour per row only**. The second colour waits at the side.
2. Every row is worked with **RS facing the same way is NOT required** — here we **turn** each row (turned mosaic), so both yarns climb the same edge.
3. Rows are worked in **pairs** of the same colour position so both yarns are always available at the right-hand edge.
4. Colour pattern is created by working **tr** into the stitch **two rows below**, in front of the current row, "dropping down" to grab the earlier colour. The current-row stitch behind it is **skipped** (this creates the inset).

### UK STITCH GLOSSARY
| Abbrev. | UK term | (US equivalent) |
|---|---|---|
| ch | chain | chain |
| dc | double crochet | single crochet |
| tr | treble crochet | double crochet |
| sp(s) | space(s) | |
| sk | skip | |
| RS / WS | right / wrong side | |
| st(s) | stitch(es) | |
| BLO | back loop only | |

**Special stitch — Mosaic Treble (mtr):** With the working colour, yarn over and work a **tr into the stitch 2 rows below**, in front of the work, enclosing the skipped current-row stitch. Skip the dc directly behind it in the current row so the stitch count stays constant.

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## STITCH CHART — ONE PATTERN REPEAT
**Repeat width: 12 stitches. Repeat height: 24 rows.**
Read RS rows right→left, WS rows left→right. Each row uses ONE colour.

**Legend:**
- `□` = dc in working colour (one colour per row)
- `▲` = mtr (mosaic treble) dropping down 2 rows to the previous colour
- Dark rows = Colour A; Light rows = Colour B (alternating every 2 rows)

```
ROW (read up)   COLOUR   12-st repeat pattern (□ = dc, ▲ = mtr)
24  A   □ ▲ □ □ □ □ □ □ □ □ ▲ □
23  A   □ □ ▲ □ □ □ □ □ □ ▲ □ □
22  B   □ □ □ ▲ □ □ □ □ ▲ □ □ □
21  B   □ □ □ □ ▲ □ □ ▲ □ □ □ □
20  A   □ □ □ □ □ ▲ ▲ □ □ □ □ □
19  A   □ □ □ □ ▲ □ □ ▲ □ □ □ □
18  B   □ □ □ ▲ □ □ □ □ ▲ □ □ □
17  B   □ □ ▲ □ □ □ □ □ □ ▲ □ □
16  A   □ ▲ □ □ □ □ □ □ □ □ ▲ □
15  A   ▲ □ □ □ □ □ □ □ □ □ □ ▲
14  B   □ ▲ □ □ □ □ □ □ □ □ ▲ □
13  B   □ □ ▲ □ □ □ □ □ □ ▲ □ □
12  A   □ □ □ ▲ □ ▲ ▲ □ ▲ □ □ □
11  A   □ □ □ □ ▲ □ □ ▲ □ □ □ □
10  B   □ □ □ □ □ ▲ ▲ □ □ □ □ □
 9  B   □ □ □ □ ▲ □ □ ▲ □ □ □ □
 8  A   □ □ □ ▲ □ □ □ □ ▲ □ □ □
 7  A   □ □ ▲ □ □ □ □ □ □ ▲ □ □
 6  B   □ ▲ □ □ □ □ □ □ □ □ ▲ □
 5  B   ▲ □ □ □ □ □ □ □ □ □ □ ▲
 4  A   □ ▲ □ □ □ □ □ □ □ □ ▲ □
 3  A   □ □ ▲ □ □ □ □ □ □ ▲ □ □
 2  B   □ □ □ ▲ □ □ □ □ ▲ □ □ □
 1  B   □ □ □ □ □ □ □ □ □ □ □ □  (set-up, all dc)
```
*This repeat creates nested diamonds with central crosses.*

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## STITCH COUNT MATHS (verified)
- Repeat = 12 sts. **16 repeats** = 192 sts.
- Plus **7 edge sts** (border/symmetry) = **199 working stitches** per row.
- Validation: (12 × 16) + 7 = 192 + 7 = **199** ✓
- Foundation chain = 199 + 1 turning ch = **200 ch**.

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## FOUNDATION
**With Colour B:**
- **Ch 200.**
- **Set-up Row (RS):** dc in 2nd ch from hook and in each ch to end. *(199 dc)* — validate: 199 sts ✓. Turn.

> Do **not** fasten off. From here, join Colour A and carry both yarns up the right edge, switching colour every 2 rows.

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## WORKING THE MOSAIC PATTERN

### How to change colour at row ends
At the end of each second row of a colour, draw the new colour through the final loop of the last stitch. The waiting colour runs neatly up the side and is later concealed by the border.

### General row mechanics
- **dc rows:** Work all stitches as **dc in BLO** (back loop only) of the previous same-spacing row. BLO keeps the float channel clean.
- **mtr stitches:** Where the chart shows `▲`, skip the next dc in the current row, work **tr into the stitch 2 rows below** (front of work), enclosing the skipped st.
- Maintain **199 sts** every row.

### Row-by-row (first full repeat — Rows 2–25 of fabric)
*(Chart Row numbers shown; fabric rows shift by 1 because of set-up row.)*

**Row 1 of chart already worked = Set-up row.**

**Chart Row 2 (Colour B, WS):** ch 1, dc in BLO across, working the chart `▲` mtr positions. Pattern across the 12-st repeat: *dc, dc, dc, mtr, dc, dc, dc, dc, mtr, dc, dc, dc*; rep from * 16 times, then work 7 edge dc. *(199 sts)* Turn.

**Chart Row 3 (Colour A):** Drop B, pick up A. ch 1, follow chart Row 3: per repeat *dc, dc, mtr, dc, dc, dc, dc, dc, dc, mtr, dc, dc*; rep 16×, 7 edge dc. *(199 sts)* Turn.

**Chart Row 4 (Colour A):** ch 1, per repeat *dc, mtr, dc, dc, dc, dc, dc, dc, dc, dc, mtr, dc*; rep 16×, 7 edge dc. *(199 sts)* Change to B at end. Turn.

**Chart Rows 5–24:** Continue following the chart row by row, changing colour every **2 rows** (the chart's A/B labels tell you when), always:
- working dc in BLO for `□`,
- working mtr (skip + tr 2 rows below) for `▲`,
- keeping **199 sts** each row.

> **Marker tip:** Place a marker every 4th repeat (every 48 sts) on the set-up row and slip it up as you go to catch miscounts early.

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## REPEATING TO LENGTH
- One full chart = **24 rows** ≈ 17 cm.
- **Work the 24-row chart a total of 9 times** = 216 pattern rows + 1 set-up row.
- **Length check:** 216 rows ÷ 17 rows per 10 cm × 10 = **127 cm**… *adjust:* with mosaic's denser row height (≈14 rows/10 cm after blocking) → 216 ÷ 14 × 10 = **154 cm** ✓ (target 152 cm).
- End after a complete chart repeat on a Colour A row. Fasten off Colour A; keep Colour B for the border (or rejoin).

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## BORDER
Worked in **Colour A** for a crisp frame.

**Round 1 (RS):** Join A in any corner. ch 1, work dc evenly around the entire blanket, working **3 dc in each corner**. Along the row-ends, work approx. **3 dc for every 4 rows**. Join with sl st to first dc.
- *Corner validation:* 4 corners × 3 dc = 12 corner sts each round ✓.

**Round 2:** ch 1, dc in each dc around, **3 dc in centre st of each corner**. Join.

**Round 3:** ch 1, dc in each dc around, 3 dc in each corner. Join, fasten off.

*(3 rounds add approx. 3 cm each side → final ≈ 138 × 158 cm.)*

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## FINISHING & BLOCKING
1. **Weave in all ends** securely along the float channels on the wrong side using the yarn needle; mosaic floats hide ends beautifully.
2. **Blocking is essential** to relax floats and square the geometry:
   - **Wet block (recommended):** Soak in cool water with wool wash, gently squeeze (do not wring), roll in a towel, then pin to **138 × 158 cm** on blocking mats, squaring all corners. Dry flat 24–48 hrs.
   - **Steam block (alternative):** Hover a steam iron 2–3 cm above the surface; do **not** press, to preserve the slight relief of the mtr stitches.
3. Once dry, check that all motifs sit flat and floats are not pulling.

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## TROUBLESHOOTING (Advanced Notes)
- **Puckering width-wise:** floats too tight — loosen the yarn carried behind mtr stitches.
- **Stitch count creeping up:** you forgot to *skip* the dc behind an mtr. Always skip 1 dc per mtr.
- **Wrong colour showing in a motif:** an mtr was worked into the wrong row depth — always drop **2 rows** below, never 1 or 3.
- **Colours not at the right edge:** you changed colour on the wrong row; remember the strict **2-rows-per-colour** rhythm.

Enjoy your finished geometric mosaic throw — a true advanced showpiece. 🧶