pxart paste

paste SRC[+h|+v|+hv] --into DST[:frame] --at x,y [--region x,y,w,h] [--under] [--rekey [KEYS]] [--variant-map NAME=V1,V2] [--align shift|pivot|bottom|bbox] [-o OUT]

usage: pxart paste [-h] --into INTO --at AT [--region REGION] [-o O] [--under]
                   [--align {shift,pivot,bottom,bbox}] [--keys K,L] [--rekey [KEYS]]
                   [--variant-map NAME=V1,V2] [--dry-run]
                   src

  paste SRC[+h|+v|+hv] --into DST[:frame] --at x,y [--region x,y,w,h] [--under] [--rekey [KEYS]]
        [--variant-map NAME=V1,V2] [--align shift|pivot|bottom|bbox] [-o OUT]
      Copy one frame (or a region of it) onto another at x,y; '.' never overwrites.

positional arguments:
  src

options:
  -h, --help                         show this help message and exit
  --into INTO
  --at AT
  --region REGION
  -o O
  --under                            only onto --into's empty pixels (behind what's there)
  --align {shift,pivot,bottom,bbox}  into several frames: --at is for the first, and the paste moves in each other frame as the body does: shift, by the best shifts anim prints, added up from the first frame (a glow following a bob, wings and all); pivot, as its pivot; bottom, as its drawing's bottom row; bbox, as its drawing's top-left (wings or an arm sticking out move it too)
  --keys K,L                         --align follows only these keys' pixels (the body, not the wings)
  --rekey [KEYS]                     give keys that clash with OUT's colors free keys in OUT only; the source files stay as they are. KEYS: only these ('o,r'), or KEY=OUTKEY to use OUT's key ('k=j,n=q')
  --variant-map NAME=V1,V2           OUT's variant NAME takes each source's first of NAME, V1, V2 (repeatable)
  --dry-run                          print what the edit says and a diff of the file it would change; write nothing

      Copy SRC's frame (or --region of it) onto DST at x,y; '.' never overwrites. +h / +v
      mirror SRC first, as for compose layers and scene items (--region is then in the
      mirrored frame's coordinates). --under fills only DST's empty pixels: SRC goes behind.
      SRC's keys join DST as a compose layer's join an existing OUT: E_KEY_CONFLICT, the
      variant WARNINGs, --rekey [KEYS] and --variant-map work alike. --align: one paste
      follows a bob across frames.

See also, in pxart help all: compose (OUT's palette, frame placement, E_KEY_CONFLICT,
  --rekey); EDITING (-o OUT gets the whole file, only changed lines are rewritten, 'no
  change'); FORMAT: selecting frames (FILE:SEL, an unnamed grid's name, zsh's "${F}:sel").

pxart help all has the whole reference, pxart help TOPIC one part of it.

This is the output of pxart help paste. The other editing commands and their shared notes are in pxart help EDITING.