How to uncurl stockinette stitch after the project is completed?

I have used size 6 acrylic yarn to knit a big blanket. it’s all in stockinette stitch and all four sides are curling. Is there anyway I can stop them even though I am done and have already casted off?

Stockinette is going to curl. It’s the nature of the stitch pattern.
Steam blocking may be the best answer. Check the ballband from your yarn or make a small test swatch to try this out and take seriously the warning about not touching the iron to the blanket. See also the accompanying video here.

You can try putting a fairly wide border onto the blanket in some flat stitch pattern to see if that helps. Garter stitch or seed stitch for example may help but won’t be completely successful at stopping the curl or flip.

Thank you! I have looked into it and think I will be steam blocking.

Hello! I am new to this forum and I thought I could post my question in this thread because it is relevant. I am knitting a hat with a cabled brim.

(CO 160 stitches. Set-up row: K2 in MC, K2 in CC. Begin Cable Pattern R1: C4B. Repeat to end of round. R2: K2 MC, K2 CC, repeat to end of round. R3: C4F. Repeat to end of round. R4: K2 CC, K2 MC, repeat to end of round). Repeat Rows 1-4 2 times and then rows 1-3 once more (11 cable rows)

The rest is striped in stockinette with the 2 colors. I did this and the brim of my hat is ROLLING!!! I know its not a traditional rib but I thought the cabling would stop the hat brim from rolling!!! I am using Cascade 220 in a DK weight (100% wool)…I have heard blocking doesn’t always help with brim rolling and I do not know how to get the brim to un-roll other than blocking…my friend suggesting sewing a piece of yarn around the edge of the brim and slightly cinching it but does anyone have any other suggestions? THANKS A LOT!

Welcome to KH!
I’d try blocking first because it’s wool. Cascade 220 usually responds well.
Wash the hat in mild soap or wool wash like Euclan or Soak, and press out excess water by rolling in a towel. I would pin the hat flat to a towel or blocking board and let it dry for days till it’s absolutely, positively dry.
Alternatively you could stuff the hat with a towel for a kind of 3D block rather than flat and then pin the brim down to the towel.
See if that works first before going to any other solution.

Also remember that it likely won’t curl when it’s on so curling when it’s off isn’t really a big deal on a hat. Or that’s how it seems to me…