Activity 002: Specialty Substrate Pressing — Mug or Hat Application

Activity ID: U9M4-ACT-002 Duration: 45 minutes Objective: Apply a heat transfer to a specialty substrate (mug or hat) using the appropriate press attachment, demonstrating correct parameter selection and quality evaluation.

Overview

Students use a specialty press attachment to apply a transfer to a non-flat substrate. For the mug option, students apply a sublimation transfer to a ceramic mug. For the hat option, students apply an HTV design to a baseball cap. Both options teach adaptation of flat-press skills to specialty equipment.

Materials & Equipment Needed

Option A: Mug Press

• Mug press attachment
• 11oz sublimation-coated ceramic mug (white)
• Pre-printed sublimation transfer (8.5" × 3.5" design on sublimation paper)
• Heat-resistant tape
• Heat-resistant gloves
• Timer
• Inspection worksheet

Option B: Hat Press

• Hat press attachment
• Structured or unstructured baseball cap (cotton or polyester)
• Pre-cut and weeded HTV design (sized for cap front: max 3.5" × 2.5")
• Teflon sheet (small)
• Heat-resistant gloves
• Timer
• Inspection worksheet

Instructions & Procedure

Option A: Mug Press

Phase 1: Preparation (8 minutes)

1. Preheat the mug press to 380°F. Allow 10 minutes to stabilize.
2. While the press heats, prepare the transfer:
3. Trim the sublimation paper to approximately 9" × 3.75" (slightly larger than the print area).
4. Wrap the paper around the mug with the printed side facing the mug surface.
5. Align the design. The top and bottom edges of the print should be parallel to the rim and base.
6. Secure both ends of the paper with heat-resistant tape (Kapton tape).
7. Ensure the paper is smooth against the mug—no wrinkles or gaps.
8. Clean the mug surface with a lint-free cloth before wrapping (fingerprints can affect sublimation).

Phase 2: Pressing (10 minutes)

1. Open the mug press element.
2. Insert the wrapped mug into the press. The heating element should wrap evenly around the mug.
3. Close the clamp firmly. The element should be snug against the mug surface with consistent pressure.
4. Set the timer: 210 seconds (3.5 minutes) at 380°F.
5. Start the timer.
6. Do not adjust the mug or element during pressing.
7. When the timer sounds, open the clamp.
8. Using heat-resistant gloves, remove the mug.
9. Immediately and carefully remove the transfer paper (peel away from you—the paper and mug are extremely hot).
10. Set the mug on a heat-resistant surface to cool. Do not submerge in water (thermal shock can crack the mug).

Phase 3: Inspection (5 minutes)

1. Allow the mug to cool for 2-3 minutes.
2. Inspect the transfer:
3. Color vibrancy: compare to the original proof
4. Coverage: complete transfer with no white gaps
5. Ghosting: any double or blurred images?
6. Edge quality: clean transitions at design borders
7. Record observations on the inspection worksheet.

Option B: Hat Press

Phase 1: Preparation (8 minutes)

1. Preheat the hat press to 305°F. Allow 10 minutes to stabilize.
2. If the cap is unstructured, insert a heat-resistant form (foam or cardboard) inside to maintain shape.
3. Position the pre-weeded HTV design on the cap front panel:
4. Center the design on the panel
5. Position below the seam/button and above the brim
6. Carrier side faces up, vinyl touches the fabric
7. Place a small Teflon sheet over the design.

Phase 2: Pressing (8 minutes)

1. Position the cap on the lower curved platen.
2. Ensure the design area is centered under the heating element.
3. Close the press. Adjust pressure if needed.
4. Set timer: 12 seconds at 305°F, medium pressure.
5. When the timer sounds, open the press.
6. Peel the carrier (hot or cold per HTV type).
7. Re-press through a Teflon sheet for 3 seconds (post-press).

Phase 3: Inspection (5 minutes)

1. Allow to cool briefly.
2. Inspect:
3. Adhesion: fingernail edge test
4. Placement: centered, level, appropriate distance from hardware
5. Surface quality: no wrinkles, bubbles, or scorching
6. Cap integrity: no heat damage to the cap structure
7. Record observations.

Phase 4: Both Options — Comparison and Discussion (14 minutes)

1. Compare your specialty substrate result to a flat garment press (from previous activities).
2. What was different about the workflow?
3. What new challenges did the specialty substrate present?
4. What would you do differently next time?
5. Complete the inspection worksheet with final ratings.

Discussion Points

• How did the curved surface affect application technique?
• For mugs: why must the paper be removed immediately after pressing?
• For hats: how did the cap hardware affect design placement?
• What other specialty substrates could be pressed with additional attachments?

Expected Outcomes

• Successfully transferred design to specialty substrate
• Correct parameter selection for the substrate type
• Clean, professional-quality result
• Understanding of how specialty pressing differs from flat pressing

Assessment Rubric

Criteria	Excellent (4)	Proficient (3)	Developing (2)	Beginning (1)
Setup	Correct parameters, proper preparation	Minor preparation oversight	Required guidance on setup	Cannot set up specialty press
Execution	Smooth process, correct timing	Minor timing issue	Significant process error	Cannot complete pressing
Result Quality	Professional quality, no defects	Minor defect (small ghosting or adhesion issue)	Noticeable defect	Failed transfer
Documentation	Complete inspection with accurate observations	Minor omissions	Significant gaps	No documentation

Safety Considerations

• Specialty substrates (especially mugs) retain heat for 5+ minutes—always use heat-resistant gloves
• Never submerge a hot mug in cold water—thermal shock can crack the mug, sending hot ceramic and water in all directions
• Hat press hardware (snaps, buttons) can become extremely hot—do not touch immediately after pressing
• The mug press heating element is exposed when open—never touch the inner surface
• Keep the workspace clear—hot mugs and substrates need a designated cooling area away from work surfaces

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Last Updated: 2026-03-19