In most failed applications, heat wasn’t the villain—pressure was. Kangaroo pocket seams, zipper boxes, cover-stitch ridges, and rib knits lift the surface and starve edges. DTF pressure mapping is how production teams diagnose those height changes, choose the right support, and keep edges clean at volume.
This guide gives you a practical decision system for heat press pads, heat press pillows, and DTF shims, plus routing tips for mixed garments, gang-sheet planning for bulk DTF transfers, and operator habits that help you hit rush DTF orders and same-day windows reliably.
Table of Contents
- Why contact geometry decides outcomes
- Pad vs. pillow vs. shim: what each does (and when)
- Fast mapping methods without special tools
- Routing by garment and placement (tees, fleece, zips, bags)
- Operator cadence: station kits, swaps, and QC
- Gang sheets, reorders, and the ordering flow
Why contact geometry decides outcomes
A press closes against the highest point first. If that “first touch” is a pocket lip or zipper rail, clamp force concentrates there while nearby graphic edges float. Over-tightening only crushes loft or telegraphs ridges through the face. Even pressure DTF is about making the print field and nearby obstacles share the same plane so adhesive engages fibers uniformly. Once the plane is flat, the rest of the process becomes predictable—edges stop scuffing on peel, tiny curves stay intact, and you can keep a single-operator station moving on mixed stacks.
Pad vs. pillow vs. shim: what each does (and when)
Pads are firm, low-compress supports that raise the print zone to the level of nearby obstacles. Use them when the art sits on a fundamentally flat panel (chest badge, number set, centered back) but lives close to cover-stitch ridges or a pocket top. Because pads barely deflect, they preserve crisp edges on smooth jersey and prevent “sink” artifacts on compact knits.
Pillows compress where hardware intrudes. They let protrusions sink—zippers, snaps, rivets, embroidery stacks—so the art stays flat while hard parts are cushioned. They’re perfect for zip hoodies, jackets, and hardware-heavy totes. Trade-off: on very thin blanks with high-detail logos, too much give can introduce micro waviness; in that case, park a small pad under the art and a pillow under the obstacle.
Shims are slim, local risers that lift one ridge or one side by a hair. Think felt or board strips positioned under a pocket lip, side seam, or piping. Shims shine when the obstruction is linear and predictable. Most shops pair shims with pads: pad under the graphic; shim under the ridge so both meet the clamp together. Because shims are modular, operators can tune the bite in seconds—no re-platening.
Decision cues (use in the print room)
- If a carrier snags on a seam → pad the graphic or shim the seam.
- If hardware telegraphs through the face → put the hardware over a pillow, keep the art on firm support.
- If edges look starved only on one side → micro-shim that side until peel feels uniform.
Fast mapping methods without special tools
Carrier-glide check.
Place the printed film where it will live and glide a fingertip across it. Any catch tells you a ridge is higher than the print field. Decide: pad under the art or shim under the ridge.
Paper emboss read. Close on a plain sheet once. Brightly burnished lines mark high points; dull regions mark low compression. Add or subtract supports until the sheen is even across the print zone.
Card sweep.
With the blank on the platen, sweep a thin card outward from center. Where it jams, you’ve hit a ridge that must either hang off the platen edge or be matched with a shim.
Off-edge when possible.
If the obstruction runs straight (pocket top, jacket hem), slide the garment so the ridge hangs off the platen while the graphic stays fully supported—fastest “shim” you own.
Routing by garment and placement (tees, fleece, zips, bags)
Jersey tees.
Most chest and back hits are pad-free. Thick shoulder joins or side-seam back prints benefit from a slim pad to keep the bite even. Sleeve crests are cleanest when the sleeve seam is off-edge; if you must print over it, micro-shim each side to prevent a see-saw effect.
Fleece hoodies.
The kangaroo pocket lip and belly cover-stitch create high/low zones. Size a firm pad slightly larger than the artwork so the hoodie pocket print plane sits higher than the ridge; if the lip still dominates, add a narrow shim under the lip. For sleeves, keep rib cuffs off the platen or isolate them with a pillow + pad pairing so the valleys don’t starve.
Zip hoodies and jackets.
Place a pillow under the zipper channel so rails sink, then land the chest badge on a small pad. For tall back graphics that pass near the zipper box seam, shim the seam line lightly rather than over-padding the whole back.
Canvas totes and structured bags.
Piping and rivets want pillows; a board-style shim under piping stops edge starvation. For gusseted totes, pad inside the body panel, not across the gusset fold, to avoid a “hinge” line through the art.
Hats and odd shapes.
Micro pillows tame crown seams; local shims even out panel transitions for small crests. Keep the art on the flattest panel and let curved seams sink.
Operator cadence: station kits, swaps, and QC
Pressure control is fastest when it’s productized as a kit. Build two labeled kits and store them at the press:
- Firm Leveling Kit (pads + thin shims) for jersey, centered backs, and badges.
- Conform Kit (pillows + wider shims) for zips, hardware, and multi-panel shapes.
Start each stack with a thirty-second touch test: with supports placed, tap around the print area; it should feel uniformly “solid.” Log a single dry close after swapping from tees to fleece or from flat backs to hardware hits—operators catch 90% of pressure misses right there.
For exit QC on rush DTF orders, pull one piece per size curve. Pinch an outer corner and a mid-edge; they should feel equally firm. If an edge reads soft, it’s almost always a support slip (not a heat miss)—re-level and keep running.
Shops that operationalize this cadence find they can move from one approved sample to consistent custom DTF transfers across tees, hoodies, and bags without redesigning placements. Many of those teams note that Sumotransfers masters remain stable across reorders because the physical support recipe doesn’t change when the artwork doesn’t change.
Gang sheets, reorders, and the ordering flow
Pressure mapping actually begins in file planning. Keep related placements together so physical supports stay constant from proof to reorder.
- Build one master per design family in the DTF gang sheet builder and label variants inside the art—“front-badge,” “sleeve-crest,” “back-center.” Group youth and adult in the same master so alignment and spacing remain consistent across bodies.
- For precise badges or sleeve tags, start from custom DTF by size. Lock the physical size once; reuse it for every colorway and garment type so your pad/pillow/shim recipe never drifts.
- If you decorate later in-house, stock film via Ready to Press DTF and keep approved masters shelved by placement. That way, the same station kit applies whether you’re pressing tees today or hoodies next week.
- Tight calendar? Confirm carrier windows and cutoff notes on Shipping & Delivery, and park edge-case questions with FAQ/Support before the queue closes.
Pressure mapping isn’t an art project; it’s a repeatable layout problem. Once your team can identify what’s taller than the print field and choose pad vs. pillow vs. shim on instinct, mixed garments stop being “special cases” and become ordinary line items you can run at speed.
Ready to standardize DTF pressure mapping and keep edges clean on every garment? Build your masters in the custom-by-size flow at Sumotransfers and route pads, pillows, and shims with confidence.