This Rompers – Half Sleeve pattern, also recognized as Regular Rompers, is an infant one-piece calibrated for comfort, diaper volume, and easy dressing. The block uses a crew neckline with a knit rib neckband to maintain opening stability without harsh rigidity. Half sleeves balance coverage and mobility; hem and sleeve openings are finished cleanly to avoid abrasive edges on delicate skin. The size range spans 0M3, 3M6, 6M12, 12M18, and 18M24. Grading advances in measured steps across chest 18–26, shoulder width 8–12, and sleeve length 3.5–5.5, providing progressive ease as babies grow. Body length increases through sizes; pattern proportion preserves a diaper-friendly rise and adequate stride room to prevent seam stress during crawling. Snap closure at the crotch enables quick changes; snap positions are plotted for even load distribution to reduce tearing at the placket ends. Construction emphasizes soft, secure internals: primary assembly on 4‑thread overlock for elastic seams, with coverstitched hems to keep bulk low and prevent rolling. Stress areas (crotch placket ends and shoulder intersections) receive discrete reinforcements using self fabric to spread load while keeping touchpoints smooth. Threads are locked and trimmed to eliminate loose tails. Cutting and pattern-making are executed from CAD-generated performas with layered manual cutting, ensuring consistent rib circumference, snap alignment, and mirrored leg curves across all sizes. This approach maintains tight grading control so chest, shoulder, and snap placements remain consistent program to program based on our infant fit R&D.