Printable 2x8 inch bookmark is 1:4: cost of 6 to 24 designs

A 2 by 8 inch bookmark is exactly 1:4, which Nano Banana 2.1 lists on Sume, so you can generate the print shape instead of cropping a poster. At 300 dpi the target is 600 by 2400 pixels; one design costs $0.15 at 2K or $0.20 at 4K.

Cost per set of designs

Request

Use the same prompt skeleton for a set so the designs feel like a series; change one subject per call.

import os, requests

body = {
    "model": "google/nano-banana-2.1",
    "prompt": "Bookmark design, botanical pattern in teal and gold, tall vertical layout, space for a small title near the top",
    "aspect_ratio": "1:4",
    "resolution": "2K",
}
r = requests.post(
    "https://api.sume.com/v1/images",
    headers={"Authorization": f"Bearer {os.environ['SUME_API_KEY']}"},
    json=body, timeout=60,
)
print(r.status_code)  # 200 = image body, 202 = job envelope
if r.status_code == 200:
    out = r.json()
    print(out["data"][0]["url"], out["usage"]["cost"])

Check pixels before you print

The request chooses a tier, not exact pixels, so read the downloaded file's width and height. If it is below 600 by 2400, upscale it or move to 4K. A 600 by 2400 target at 300 dpi gives a print of exactly 2 by 8 inches; print shops usually also want bleed, so ask for extra background around the edges and trim.

Gotchas

• Keep the title off the edges: a tall print trims unevenly.
• Run a test print of one design before you generate 24.
• Color in print differs from the screen; ask your printer for their profile.