The stitch in the image you provided is a Tunisian crochet pattern, specifically the Tunisian Full Stitch (TFS) or a close variation of it. This technique combines elements of knitting and crochet and uses a Tunisian crochet hook, which is longer than a regular crochet hook.
Here’s how you can make this stitch pattern:
🧵 What You’re Seeing in the Photo
- The hook is a Tunisian (Afghan) crochet hook — longer to hold multiple loops.
 - The fabric has vertical V-shaped columns, each made of two “legs” of yarn.
 - Between these columns are open mesh spaces — that’s from inserting the hook between vertical bars, not through them.
 - The result is the Tunisian Full Stitch (TFS) — airy, springy, and textured.
 

🪡 What You Need
- Tunisian crochet hook (any size, but usually 1–2 mm larger than the yarn label suggests)
 - Yarn (medium weight, light color helps you see stitches)
 - Scissors
 - Tapestry needle for finishing
 
🧶 Step-by-Step Instructions
1️⃣ Foundation Chain
- Chain any even number of stitches (plus 1 for turning).
Example: chain 21 (20 + 1). 
2️⃣ Foundation Forward Pass
- Insert your hook in the 2nd chain from the hook, yarn over (YO), pull up a loop, and leave it on the hook.
 - Continue pulling up a loop in each chain to the end.
→ You’ll now have one loop on your hook per chain. 
3️⃣ Foundation Return Pass
- YO and pull through 1 loop only (creates the edge chain).
 - YO and pull through 2 loops at a time across the row.
→ You end with 1 loop left on your hook. 

4️⃣ Tunisian Full Stitch Rows
Forward Pass
- Instead of inserting under a bar, insert your hook between the vertical bars of the previous row (the space between columns).
 - YO and pull up a loop; keep it on the hook.
 - Repeat this across the row.
 - For the last stitch, insert your hook through the two end loops on the side edge, YO, pull up a loop.
 
You should now have a row of loops on your hook again.
Return Pass
- YO and pull through 1 loop only (edge chain).
 - YO and pull through 2 loops repeatedly until 1 loop remains on the hook.
 
That completes one TFS row.

5️⃣ Repeat Rows
- For each new row, you’ll alternate the spaces where you insert your hook:
- Row 2: Start inserting after the first vertical bar.
 - Row 3: Start inserting before the first vertical bar.
 
 - Alternating rows like this keeps the mesh even and creates that subtle diagonal texture.
 

🧩 Optional Edge Finishing
Because Tunisian crochet tends to curl:
- Work a final slip-stitch row (insert under each vertical bar, YO, pull through both loops).
 - Or border it with single crochet stitches all around.
 - Steam-block or wet-block your piece flat.
 
🧠 Troubleshooting
| Issue | Likely Cause | Fix | 
|---|---|---|
| Fabric curling | Normal for Tunisian | Block or use larger hook | 
| Tight edges | First chain/return pass too tight | Use looser tension | 
| Uneven mesh | Skipping spaces inconsistently | Be sure to alternate row starting point | 
🧵 Quick Pattern Summary
Ch any even number + 1
Foundation Forward Pass: Pull up loops in each ch
Return Pass: YO, pull through 1, then YO pull through 2 across
Row 1 (TFS): Insert between vertical bars, pull up loop across
Return Pass
Row 2: Start between 2nd and 3rd vertical bars, pull up loop across
Return Pass
Repeat Rows 1–2