Costume Clip

Costume Clip or Costume Change Clip, is a method of clipping through solid objects by abusing the temporary loss of collision from switching costumes. When selecting a costume that you have saved into your popit. Sackboy will lose all collision for 1 single frame, allowing you to more easily clip through walls with enough speed. The technique works in all 3 mainline LBP games; however, it's an incredibly difficult trick to perform, only currently being implemented in a select few IL speedruns.

Tutorial

Before performing a Costume Clip, you must have a costume with a sticker attached to it saved into your popit. Once you do this a single time, the technique will permanently work on your profile regardless of what costume you are selecting (even if it isn't the specific costume with the sticker). Without doing this, switching your costume will not remove your collision and the trick is impossible.

To make it easier to quickly switch costumes, add the saved costume to your favorites page by hearting it. Selecting the costume from the favorites page instead will avoid the camera zooming in from opening the costume menu, and prevent you from selecting the wrong item when quickly switching costumes.

If you're performing a costume clip during a full-game LBP1 run, you can save a costume with a sticker during the draw bridge section of First Steps. Place the shoe sticker onto yourself after activating the sticker sensor, then save and heart your costume while waiting for the bridge to be lowered.