A normal crochet stitch usually has a V-shaped top made from two strands. Working through both gives one fabric; using just the front or back strand can create ridges and change how the fabric moves. The important detail is that front and back are identified from the side currently facing you.
Stitch terminology: This guide uses US names. US single crochet is UK double crochet; US half double is UK half treble; US double is UK treble. See the full US/UK reference.
Look down at the stitch top
The strand nearest you is the front loop. The strand farther away is the back loop. When you turn the work, the relationship changes. Do not keep reaching for the strand that used to be at the back merely because you remember its previous position.
| Instruction | Hook placement | Unworked strand |
|---|---|---|
| Both loops | Under both strands of the top V | Neither |
| FLO | Under the strand nearest you | Back loop |
| BLO | Under the strand farther from you | Front loop |
Keep the stitch movement unchanged
For back-loop single crochet, insert under the back loop and complete an ordinary single crochet. You are not making a different height of stitch. The same placement instruction can also apply to taller stitches, so read both the stitch abbreviation and the loop instruction.
“Back post” is different again. A post stitch wraps around the vertical body of a stitch; it does not simply use the back strand of the top V.
Make three comparison strips
Begin each strip with thirteen chains and a first row of twelve single crochets. Keep the yarn and hook the same. On later rows, work one strip through both loops, one through front loops only and one through back loops only. Chain one without counting it and retain twelve stitches per row.
Label the strips before putting them down. Compare their ridges, thickness and stretch after the yarn’s normal care routine. Your own samples are more useful than assuming every fibre will react identically to a particular loop choice.
Read what the ridge is telling you
An unworked loop can remain visible as a line across the fabric. If one unexpected ridge appears in a plain both-loop project, inspect the row immediately above it. You may have worked into only one loop without intending to.
If the change was accidental and is close to the working edge, undoing that row is often the clearest fix. If it is far back, decide whether the texture affects the intended use before removing hours of work.
Do not substitute loop placement casually in shaping
Changing loop placement can affect gaps around increases and decreases. An invisible decrease intended for ordinary single-crochet amigurumi does not necessarily give the same result in back-loop-only fabric.
Likewise, a pattern may leave loops free so that another colour, border or raised stitch can use them later. Working through both loops at that stage would remove those attachment points.
Use markers to make the change intentional
When a pattern switches between both loops and one loop, mark the first stitch of the new section. Read the instruction again after a break. A tiny note saying “BLO until marker” can prevent an entire round of correct stitches being placed in the wrong part of the fabric.
Continue learning
Find the half-double third loop · Use back-loop rows for ribbing · Choose the correct decrease
Browse the crochet learning library.