Draw images on a canvas next to each other without space in flutter - flutter

Question

I'm creating a game in flutter. I'm using a tilesheet to render tiles. I chop the image in 50x50 sections and then render them depending on their surrounding.
The tiles are rendered at the position of their corresponding "game object". In order to keep the code clean from details about converting from the game world positions and sizes to actual screen sizes my painting classes always obtain world space and then scales it up to screen space.
However, after scaling up the tiles I'm sometimes left with gaps between the tiles.
I've tried:
Placing the tiles at their appropriate screen position, without scaling the canvas first, in case the scaling produces the problem.
Adding borders around the tiles in the tilesheet in case the canvas.drawImageRect samples too many pixels.
Making the board take a size divisible by the number of tiles, in case there is a rounding error.
Drawing a subsection of the tile.
I can't seem to make the gap disappear. Do you have any suggestions?
Below is the relevant drawing code, where size and position are in world space and frameX and frameY is the positions to extract from the spritesheet.
void drawFrameAt(int x, int y, Canvas canvas, Offset position, Size size) {
var frameX = x * frameWidth;
var frameY = y * frameHeight;
var rect = Rect.fromLTWH(frameX, frameY, frameWidth, frameHeight);
var width = size.width;
var height = size.height;
var destination = Rect.fromLTWH(position.dx, position.dy, width, height);
canvas.drawImageRect(image, rect, destination, Paint());
}