How to Fix a Warped Warhammer Poster

Quick answer

For a mildly warped Warhammer poster, lay it print-side up on a clean, flat surface, cover it with a clean cotton sheet, and stack flat, heavy books or boards evenly across the whole sheet. Leave it 24 to 48 hours. If it is still curled, try 10 to 15 minutes under a low-heat iron with no steam, pressing through the sheet. If the paper feels brittle or the ink is cracking, stop — replacement is the safer option.

A warped poster is rarely ruined — but the wrong fix can turn a curl into a crease. Warhammer wall art usually warps for one of three reasons: it was rolled too tightly, it was stored somewhere damp, or it was hung without enough support. Each cause needs a different response, so diagnose before you press.

This guide walks through the symptom, the likely cause, the corrective action, and the point where you should stop and choose another option. It focuses on paper posters and prints; banners and fabric wall art behave differently and are covered by their own care advice.

Identify the warp before you try to fix it

Look at the shape, not just the curl. A gentle bow across the whole sheet usually means storage or hanging pressure. Tight, tube-shaped curls at one or both ends point to long-term rolling. Wavy, rippled edges that feel slightly soft or cool often mean moisture was involved, and that is the case where heat does the most damage.

Run a clean finger along the back of the paper. If it feels crisp and dry, you are probably dealing with a mechanical curl and weight flattening is safe. If it feels clammy, limp, or has a faint musty smell, let it air-dry flat in a dry room for a day before applying any weight. Pressing damp paper traps moisture and can cause mould or ink lift.

• Check the printed side under a lamp: hairline cracks in the ink mean the coating is already stressed, so skip heat entirely.
• Note whether the warp is across the whole sheet or only at the ends — it changes which method to use.

Flatten a curled poster with even weight

This is the safest method for most paper posters. Work on a hard, clean, dry surface — a tabletop, not carpet. Place the poster print-side up, then lay a clean cotton sheet or acid-free tissue over it. Build a flat stack of large books or boards that covers the entire poster, not just the middle, because concentrated weight in one spot creates new creases.

Leave it for 24 to 48 hours at room temperature. For a stubborn end curl, reverse the roll gently by hand first — never force it — then weight it. If the poster has been rolled for months, expect to repeat the cycle two or three times. Patience here is cheaper than replacing the print.

• Use boards larger than the poster so edges are supported too.
• Keep the stack away from radiators, windows, and damp floors while it flattens.

Use low heat only as a second attempt

If weight alone has not worked after two days, heat can relax paper fibres — but it is a one-way risk. Set an iron to its lowest setting, switch off steam completely, and place a clean cotton sheet between the iron and the poster. Press evenly with light pressure, moving continuously, for 10 to 15 seconds per area, then check the result before continuing.

Total ironing time should stay around 10 to 15 minutes for a standard poster. Let the poster cool flat under a light weight afterwards, because paper holds the shape it cools in. Never iron directly on the printed side, never use steam, and never hold the iron still — those three mistakes cause the shiny patches and lifted ink that cannot be reversed.

• Test on a corner first and wait for it to cool before judging the result.
• If you see any gloss change or colour shift, stop immediately.

Prevent the warp from coming back

Once flat, store or display the poster so it stays flat. If you are not hanging it yet, keep it between two rigid boards in a dry room rather than re-rolling it tightly. If you are hanging it, use support along the top edge and avoid pinning only the corners, which lets the middle sag and the edges ripple over time.

Humidity is the most common repeat offender. Avoid hanging paper prints directly above kettles, in bathrooms, or against cold exterior walls where condensation forms. Fabric wall art such as a banner tolerates these conditions far better, which is worth remembering if the room itself is the problem rather than the poster.

• Rotate or re-weight stored posters once or twice a year.
• Keep paper prints out of direct sunlight to limit fading and drying.

When to stop and choose another option

Stop if the paper is brittle, if the ink is cracked or flaking, if the warp returns within a day of flattening, or if the poster has visible water staining or a musty smell. At that point you are risking further damage for a result that will not hold, and a replacement or a different format is the better spend.

If the room is damp or the poster keeps warping, switch to a fabric wall banner instead of paper. A banner is printed on polyester, tolerates humidity, and hangs flat from eyelets rather than relying on the paper staying rigid. That solves the cause rather than treating the symptom again.

• Framing is the most reliable long-term fix for a poster you have already flattened successfully.
• If you have flattened and re-hung the same poster twice with no luck, change the format, not the method.

Warp diagnosis: match the symptom to the fix

• Gentle bow across the whole sheet: Almost always storage or hanging pressure. Lay the poster print-side up, cover with a clean cotton sheet, and stack flat boards or books evenly across the full sheet for 24 to 48 hours. If it is flat after one cycle, re-hang with support along the top edge so it does not sag again.
• Tight tube curl at one or both ends: Caused by long-term tight rolling. Reverse the roll gently by hand, then weight it. Repeat the weight cycle two or three times rather than reaching for heat straight away. If the curl survives three weight cycles and the paper is still crisp, a short low-heat iron pass through a cotton sheet is the next step.
• Wavy, rippled edges that feel soft or cool: Moisture is involved. Air-dry the poster flat in a dry room for a day before applying any weight. Do not iron damp paper — trapped moisture causes mould and ink lift. If the warp returns within a day in the same spot, the room is the problem. Move the print or switch to a fabric banner.
• Brittle paper, cracked ink, staining, or musty smell: The damage is past the point where flattening helps, and further pressure or heat will make it worse. There is no safe corrective action left at home. Stop. Replace the print, or switch to a polyester wall banner that tolerates humidity and hangs flat from eyelets.

Products that suit a damp or high-traffic wall

• Warhammer The Horus Heresy Ultramarines Wall Banner: Official Warhammer The Horus Heresy Ultramarines Wall Banner, crafted from double-layered 100% polyester with reinforced overlocked edges and twin metal eyelets for display. Polyester does not absorb moisture the way paper does, so it hangs flat in rooms where a paper poster would keep warping. The eyelets spread the load along the top edge instead of pinning corners.
• Warhammer The Horus Heresy - Thousand Sons Bundle: The bundle includes the official Warhammer The Horus Heresy Thousand Sons Wall Banner, which uses a full-colour sublimation print. A sublimation print dyes the fabric rather than sitting on the surface, so there is no ink layer to crack when the piece flexes — useful if you have already lost a paper print to handling damage.
• Warhammer 40,000: Cadia Battleworn Insignia Hoodie: Official Warhammer 40,000: Cadia Battleworn Insignia Hoodie in sizes S to 5XL, 80% ringspun cotton and 20% polyester at 280gsm, with a digitally printed design. If you are re-hanging wall art above a desk or hobby table, a midweight hoodie keeps the wearer comfortable during the longer sorting and framing sessions that poster care often turns into.

Most warped Warhammer posters can be saved with even weight, patience, and a dry room — heat is a last resort, not a first move. Diagnose the cause first, stop as soon as the paper or ink tells you to, and if the same poster keeps curling, fix the environment or change the format rather than repeating the same method.