The shape of a flame

In Illustrator, we draw a schematic tongue of fire, with its tip already leaning as if something just breathed on it. We export it as a PNG.

We drop the image into a new Vexy Lines document, so it becomes the Source image.  

Horizontal heat

We add a single Linear fill that rakes the flame into level bands — slow and calm across the crest, packed tight and restless toward the base.

In Filters, we apply the Blur to the signal (the way the fill interprets the source). This allows for a gradual grow of the Stroke thickness, which modulates the font size within the thickness range (make the same min and max thickness to keep the font size constant).

We add Wobble to the fill to add some organic movement of the baselines. The Stroke interval will set the line spacing.

We draw a rectangular Mask. We leave a small opaque distance on top, left and right, and a bit more opaque distance at the bottom (where the final line of the poem will be typeset.). The mask ensures that the strokes, and therefore the text, will not touch the document edges.

(Note: The image also shows the pattern paths generated by the Linear fill. We would see these paths highlighted in the interface if we converted the Linear fill to Handmade. But we don’t need to do this conversion just yet.)

Words become fire

We add a Text fill. We hide the just-added Linear fill and specify it as the base layer for the Text fill. We pick the font Playfair Trumpet Italic. This defines the default instance value for all axes. Then we choose OpticalSize as the variable axis.

We add our text: pre-wrapped lines, each shorter than the previous one, and we choose the Line by Line repetition. Vexy Lines pours the poem into the silhouette: letters small and still at the top, swelling and breaking apart toward the roar at the base.

The brightness of the pixels chooses the instance along the variable axis — even if your stroke thickness is fixed (has no range).

Laying the embers

We create a new layer, and add a second Linear fill, which we hide. We draw a small rectangular mask at the foot of the flame. This builds the ground the flame stands on: a low bed of horizontal heat.

In this case, we’ve drawn the mask explicitly where we want the final line of text to be.  

As an alternative, we could activate Mask Overlay in the top layer: the top layer’s transparent area automatically becomes opaque in the bottom layer, ensuring that the fills across two different layers don’t overlap.

The last line

The final Text fill based on the hidden Linear fill drops the closing words into the embers: the poem’s final breath, settling as everything burns down.

For the final line of our poem text, we use the Playfair Trumpet ExtraBold Italic font instance, and we vary it the same way as in the top layer.

Always sharp, always fresh

All fills stay live and fully vector. Save the document as a .lines file. Then export it as SVG or PDF a vector document next the .lines file, and place the vector doc as a linked file or layer into your design app (Photoshop, Illustrator, InDesign, Affinity).

Tweak the artwork in Vexy Lines. Press Cmd+E or Ctrl+E — and the linked artwork refreshes in the design app. Your composition stays fresh and sharp.